Association between Lipid Ratios and Insulin Resistance in a Chinese Population

Aim

To explore the association of lipid ratios and triglyceride (TG) with insulin resistance (IR) in a Chinese population. We also provide the clinical utility of lipid ratios to identify men and women with IR.

Methods

This cross-sectional study included 614 men and 1055 women without diabetes. Insulin resistance was defined by homeostatic model assessment of IR > 2.69. Lipid ratios included the TG/ high density lipoprotein cholesterol (HDL-C), the total cholesterol (TC)/HDL-C and the low density lipoprotein cholesterol (LDL-C)/HDL –C. Logistic regression models and accurate estimates of the area under the receiver operating characteristic (AUROC) curves were obtained.

Results

In normal-weight men, none of lipid ratios nor TG was associated with IR. In overweight/obese men, normal-weight women and overweight/obese women, the TG/HDL-C, the TC/HDL-C and TG were significantly associated with IR, and the associations were independent of waist circumference. All of the AUROCs for the TG/HDL-C and TG were > 0.7. The AUROCs for TC/HDL-C ratio were 0.69–0.77. The optimal cut-offs for TG/HDL-C were 1.51 in men and 0.84 in women. The optimal cut-offs for TG were 1.78 mmol/L in men and 1.49 mmol/L in women, respectively. In men, the optimal cut-off for LDL-C/HDL-C is 3.80. In women, the optimal cut-off for LDL-C/HDL-C is 3.82.

Conclusion

The TG/HDL-C, the TC/HDL-C and TG are associated with IR in overweight/obese men, normal-weight and overweight/obese women. The LDL-C/HDL-C is only associated with IR in normal-weight women. The TG/HDL-C and TG might be used as surrogate markers for assessing IR.     

Carbohydrate intake is correlated with biomarkers for coronary heart disease in a population of overweight premenopausal women

The associations between macronutrient intake and plasma parameters associated with increased risk for coronary heart disease (CHD) were evaluated in 80 overweight premenopausal women. We hypothesized that higher carbohydrate intake would be associated with a more detrimental plasma lipid profile. Dietary data were collected using a validated food frequency questionnaire (FFQ). Plasma total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were determined from two fasting blood samples. In addition, selected apolipoproteins (apo) and LDL peak size were measured. Values for TC, TG and HDL were not in the range of risk classification; however, the mean values of LDL-C, 2.7 +/- 0.7 mmol/L, were higher than the current recommendations. Carbohydrate intake was positively associated with TG and apo C-III (P < .01) concentrations, and negatively associated with LDL diameter (P < .01). Participants were divided into low (<53% of energy) or high (> or = 53% energy) carbohydrate intake groups. Individuals in the <53% carbohydrate group consumed more cholesterol and total fat, but also had higher intake of polyunsaturated and monounsaturated fatty acids (SFAs). In contrast, subjects in the > or =53% group consumed higher concentrations of glucose and fructose than those in the low-carbohydrate (LC) group. In addition, subjects consuming <53% carbohydrate had lower concentrations of LDL-C and apo B (P < .01) and a larger LDL diameter (P < .05) than the > or =53% group. These results suggest that the lower LDL-C in the LC group may be related to both the amount of carbohydrate and the type of fatty acids consumed by these subjects.     

One-year effects of increasingly fat-restricted, carbohydrate-enriched diets on lipoprotein levels in free-living subjects

Restriction of all dietary fat is a popular strategy for restricting saturated fat intake to lower LDL cholesterol. Some authorities advise the restriction of fat intake to the extreme of less than 10% of daily energy on the assumption that more fat restriction is better. The two studies described herein address questions relating to whether increasing fat restriction produces proportionally increasing benefit on cardiovascular risk factors in hyperlipidemic subjects.The first study is the Dietary Alternatives Study (DAS). The DAS was conducted in 531 male Boeing employees over a 2-year period. Subjects were defined as hypercholesterolemic (HC) or combined hyperlipidemic (CHL) based on age-specific 75th percentiles for plasma LDL-C and triglyceride levels. Hypothesis test analyses were performed at 1 year. HC subjects were randomized to diets taught to attain fat intakes of 30, 26, 22, and 18% (Diets levels 1-4, respectively). CHL subjects (slightly fewer in number) were randomized to Diets 1-3. After 1 year, subjects' total fat intakes were 27, 26, 25, and 22% of energy (en%), resulting in saturated fat intakes of 8, 7, 7, and 6%, respectively. In HC subjects the greatest LDL-C decrease was with Diet 2 (mean of 13.4%) and in CHL subjects with Diet 1 (7.0%). Surprisingly, plasma triglyceride concentrations rose in HC subjects 20% and 40% above baseline on Diets 3 and 4, respectively, with reciprocal reductions in HDL cholesterol of 2.5% and 3%, respectively. Furthermore, apo B reductions were attenuated below Diet 2 in HC subjects and Diet 1 in CHL subjects, and no further reductions were seen in plasma glucose and insulin concentrations, blood pressure, or body weight. Measurements of plasma total fatty acid composition showed a slight increase in plasma palmitate, whereas stearate decreased slightly, supporting the idea that de novo synthesis of palmitic acid was increased in the chronic high-carbohydrate feeding condition. The second study asked if the most effective diet in HC subjects, Diet 2, has an equivalent effect in women and men. To answer this question, men and women Boeing employees were taught the closely similar National Cholesterol Education Program (NCEP) Step II diet. After 6 and 12 months, equivalent reductions in LDL cholesterol were observed in women compared with men. HDL cholesterol levels in men were unchanged from baseline at 6 and 12 months, but were reduced 8% in HC women, with accompanying decreases of 18% in HDL2-cholesterol and 5% in apoprotein A-I (all P < 0.01). These data indicate that intakes of fat below about 25 en% and carbohydrate intake above approximately 60 en% yield no further LDL-C lowering in HC and CHL male subjects and can be counterproductive to triglyceride, HDL-C, and apo B levels. This lack of benefit appears to be explained by an enhanced endogenous synthesis of palmitic acid, which negates the benefit of further saturated fat restriction. The HDL-C decrease in HC women may have a similar cause and points to an underlying male-female difference. Alternative dietary approaches to limit saturated fat intake deserve intensive study.     

Aerobic exercise alone results in clinically significant weight loss for men and women: Midwest exercise trial 2

Exercise is recommended by public health agencies for weight management; however, the role of exercise is generally considered secondary to energy restriction. Few studies exist that have verified completion of exercise, measured the energy expenditure of exercise, and prescribed exercise with equivalent energy expenditure across individuals and genders.

Objective:

The objective of this study was to evaluate aerobic exercise, without energy restriction, on weight loss in sedentary overweight and obese men and women.

Design and Methods:

This investigation was a randomized, controlled, efficacy trial in 141 overweight and obese participants (body mass index, 31.0 ± 4.6 kg/m²; age 22.6 ± 3.9 years). Participants were randomized (2:2:1 ratio) to exercise at either 400 kcal/session or 600 kcal/session or to a nonexercise control. Exercise was supervised, 5 days/week, for 10 months. All participants were instructed to maintain usual ad libitum diets. Because of the efficacy design, completion of ≥90% of exercise sessions was an a priori definition of per protocol, and these participants were included in the analysis.

Results:

Weight loss from baseline to 10 months for the 400 and 600 kcal/session groups was 3.9 ± 4.9 kg (4.3%) and 5.2 ± 5.6 kg (5.7%), respectively, compared with weight gain for controls of 0.5 ± 3.5 kg (0.5%) (P < 0.05). Differences for weight loss from baseline to 10 months between the exercise groups and differences between men and women within groups were not statistically significant.

Conclusions:

Supervised exercise, with equivalent energy expenditure, results in clinically significant weight loss with no significant difference between men and women.     

Effects of a hypocaloric,low-carbohydrate diet on weight loss,blood lipids,blood pressure,glucose tolerance,and body composition in free-living overweight women

The purpose of the current study was to examine the effects of a very low-carbohydrate diet on weight loss and biochemical parameters in overweight women. Twenty women completed an 8-week trial that reduced their daily carbohydrate intake from 232 to 71 g (p < 0.05) and reduced energy by 2,644 kJ/day (8,384 to 5,740 kJ, p < 0.001). The average weight loss was 5.0 kg (p < 0.0001), with a net decrease in body mass index of 1.82 kg/m2, a loss of 3.4% body fat (4 kg, p < 0.0001), and a loss of 1.0 kg lean mass (p < 0.05). There were no significant changes in fasting blood glucose, fasting serum insulin, oral glucose tolerance, free or total insulin-like growth factor-1, or total IGFBP-3. Systolicblood pressure decreased by an average of 9.0 mmHg (1 mmHg = 133.322 Pa) (p < 0.01) and diastolic blood pressure decreased by 7 mmHg (p < 0.05). Total cholesterol decreased 1.2 mM (p < 0.001), all of which was accounted for by a decrease in low-density lipoprotein cholesterol (p < 0.001) with no change in high-density lipoprotein cholesterol (baseline, 1.17 mM; week 8, 1.22 mM). Total triacylglycerol decreased 0.6 mM (p < 0.01), and the ratio of triacylglycerol/HDL also significantly decreased (baseline, 1.40; week 8, 0.87; p < 0.001). Serum beta-hydroxybutyrate concentrations rose significantly by week 2 and declined thereafter but remained significantly higher than baseline values for the duration of the intervention. Therefore, carbohydrate restriction to 70 g or less with concomitant energy restriction, without changes in protein or fat consumption, promotes weight loss, and improvements in body composition, blood pressure, and blood lipids without compromising glucose tolerance in moderately overweight women.     

TaqIB polymorphism in the CETP gene modulates the impact of HC/LF diet on the HDL profile in healthy Chinese young adults

The aim of this study was to investigate the interactions of genetic variants in the genes of cholesterol ester transfer protein (CETP) and low-density lipoprotein receptor (LDLR) with high carbohydrate and low fat (HC/LF) diet on lipid profiles in a young and healthy Chinese Han population. Fifty-six healthy subjects (22.89±1.80 years) were given washout diets of 31% fat and 54% carbohydrate for 7 days, followed by HC/LF diets of 15% fat and 70% carbohydrate for 6 days, with no total energy restriction. Serum lipid profiles at baseline, after washout and following HC/LF diets, as well as CETP and LDLR polymorphisms were analyzed. Carriers of B2 allele of CETP TaqIB polymorphism had significantly higher levels of high density lipoprotein cholesterol (HDL-C) and apo A-I in the whole study population after the diet intervention. Notably, males with CETP TaqIB B1B1 experienced significantly increased HDL-C and apo A-I after HC/LF diet. Regarding the LDLR Pvu II polymorphism, both P1P1 subjects and P2 carriers experienced decreased total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels after HC/LF diet with no statistically significant differences between the genotypes. Our results demonstrate that the elevated HDL-C levels after HC/LF diet in healthy Chinese Han youth are associated with CETP TaqI B2 allele while males with B1B1 genotype are more susceptible to the influence of HC/LF diet on their HDL-C levels. The decreased TC and LDL-C levels after HC/LF diet are not associated with LDLR Pvu II polymorphism.     

Normal vs. high‐protein weight loss diets in men: Effects on body composition and indices of metabolic syndrome

Objective:

This study assessed the effectiveness of a prescribed weight‐loss diet with 0.8 versus 1.4 g protein·kg^?1 day^?1 on changes in weight, body composition, indices of metabolic syndrome, and resting energy expenditure (REE) in overweight and obese men.

Design and Methods:

Men were randomized to groups that consumed diets containing 750 kcal day^?1 less than daily energy needs for weight maintenance with either normal protein (NP, n = 21) or higher protein (HP, n = 22) content for 12 weeks. The macronutrient distributions of the NP and HP diets were 25:60:15, and 25:50:25 percent energy from fat, carbohydrate, and protein, respectively. Assessments were made pre and post intervention. The subjects were retrospectively subgrouped into overweight and obese groups.

Results and Conclusion:

Both diet groups lost comparable body weight and fat. The HP group lost less lean body mass than the NP group (?1.9 ± 0.3 vs. ?3.0 ± 0.4 kg). The effects of protein and BMI status on lean body mass loss were additive. The reductions in total cholesterol, HDL‐C, triacylglycerol, glucose, and insulin, along with LDL‐C, total cholesterol‐to‐HDL‐C ratio, and HOMA‐IR, were not statistically different between NP and HP. Likewise, macronutrient distributions of the diet did not affect the reductions in REE, and blood pressure. In conclusion, energy restriction effectively improves multiple clinical indicators of cardiovascular health and glucose control, and consumption of a higher‐protein diet and accomplishing weight loss when overweight versus obese help men preserve lean body mass over a short period of time.

     

Effects of R219K polymorphism of ATP-binding cassette transporter 1 gene on serum lipids ratios induced by a high-carbohydrate and low-fat diet in healthy youth

Background

Diets are the important players in regulating plasma lipid profiles. And the R219K polymorphism at the gene of ATP-binding cassette transporter 1(ABCA1) was reported to be associated with the profiles. However, no efforts have been made to investigate the changes of lipid profiles after a high-carbohydrate and low-fat diet in different subjects with different genotypes of this polymorphism. This study was to evaluate the effects of ABCA1 R219K polymorphism on serum lipid and apolipoprotein (apo) ratios induced by a high-carbohydrate/low-fat (high-CHO) diet. After a washout diet of 54.1% carbohydrate for 7 days, 56 healthy young subjects (22.89 ± 1.80 years old) were given a high-CHO diet of 70.1% carbohydrate for 6 days. Height, weight, waist circumference, hip circumference, glucose (Glu), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apoA-1 and apoB-100 were measured on the 1^st, 8^th and 14^th days of this study. Body mass index (BMI), waist-to-hip ratios (WHR), log(TG/HDL-C), TC/HDL-C, LDL-C/HDL-C and apoA-1/apoB-100 were calculated. ABCA1 R219K was analyzed by a PCR-RFLP method.

Results

The results indicate that the male subjects of all the genotypes had higher WHR than their female counterparts on the 1^st, 8^th and 14^th days of this study. The male K carriers had higher log(TG/HDL-C) and TC/HDL-C than the female carriers on the 1^st and 14^th days, and higher LDL-C/HDL-C on the 14^th day. When compared with that on the 8^th day, TC/HDL-C was decreased regardless of the genotypes and genders on the 14^th day. Log(TG/HDL-C) was increased in the males with the RR genotype and the female K carriers. Lowered BMI, Glu and LDL-C/HDL-C were found in the male K carriers, but only lowered BMI in the female K carriers and only lowered LDL-C/HDL-C in the females with the RR genotype.

Conclusions

These results suggest that ABCA1 R219K polymorphism is associated differently in males and females with elevated log(TG/HDL-C) and decreased LDL-C/HDL-C induced by the high-CHO diet.     

The signal transduction pathway of PKC/NF-κB/c-fos may be involved in the influence of high glucose on the cardiomyocytes of neonatal rats

Background

Our aim was to compare the effects of a Paleolithic ('Old Stone Age') diet and a diabetes diet as generally recommended on risk factors for cardiovascular disease in patients with type 2 diabetes not treated with insulin.

Methods

In a randomized cross-over study, 13 patients with type 2 diabetes, 3 women and 10 men, were instructed to eat a Paleolithic diet based on lean meat, fish, fruits, vegetables, root vegetables, eggs and nuts; and a Diabetes diet designed in accordance with dietary guidelines during two consecutive 3-month periods. Outcome variables included changes in weight, waist circumference, serum lipids, C-reactive protein, blood pressure, glycated haemoglobin (HbA1c), and areas under the curve for plasma glucose and plasma insulin in the 75 g oral glucose tolerance test. Dietary intake was evaluated by use of 4-day weighed food records.

Results

Study participants had on average a diabetes duration of 9 years, a mean HbA1c of 6,6% units by Mono-S standard and were usually treated with metformin alone (3 subjects) or metformin in combination with a sulfonylurea (3 subjects) or a thiazolidinedione (3 subjects). Mean average dose of metformin was 1031 mg per day. Compared to the diabetes diet, the Paleolithic diet resulted in lower mean values of HbA1c (-0.4% units, p = 0.01), triacylglycerol (-0.4 mmol/L, p = 0.003), diastolic blood pressure (-4 mmHg, p = 0.03), weight (-3 kg, p = 0.01), BMI (-1 kg/m², p = 0.04) and waist circumference (-4 cm, p = 0.02), and higher mean values of high density lipoprotein cholesterol (+0.08 mmol/L, p = 0.03). The Paleolithic diet was mainly lower in cereals and dairy products, and higher in fruits, vegetables, meat and eggs, as compared with the Diabetes diet. Further, the Paleolithic diet was lower in total energy, energy density, carbohydrate, dietary glycemic load, saturated fatty acids and calcium, and higher in unsaturated fatty acids, dietary cholesterol and several vitamins. Dietary GI was slightly lower in the Paleolithic diet (GI = 50) than in the Diabetic diet (GI = 55).

Conclusion

Over a 3-month study period, a Paleolithic diet improved glycemic control and several cardiovascular risk factors compared to a Diabetes diet in patients with type 2 diabetes.

Trial registration

ClinicalTrials.gov NCT00435240.     

Physical Activity and Low-Fat Diet: Is it Enough to Maintain Weight Stability in the Reduced-Obese Individual Following Weight Loss by Drug Therapy and Energy Restriction?

DOUCET, ERIC, PASCAL IMBEAULT, NATALIE ALMÉRAS, AND ANGELO TREMBLAY. Physical activity and low-fat diet: Is it enough to maintain weight stability in the reduced-obese individual following weight loss by drug therapy and energy restriction? Obes Res. Objective: The anthropometric and physiological effects of a physical activity (PA) and a mildly energy-restricted low-fat diet (LFD) follow-up program after a long-term dietary restriction were studied in 12 men and 8 women. Research Methods and Procedures: The dietary restriction (?700 kcal/day) was accompanied by a fenfluramine (60 mg/day) or placebo treatment for 15 weeks, whereas the mean duration of the PA-LFD follow-up was 18 weeks. Results: The long-term dietary restriction reduced body weight (?11. 9 and ?7. 6 kg, p<. 001), fat mass (FM) (?10. 6 and ?5. 8 kg, p<0. 01), resting metabolic rate (RMR) (?304 kcal/day, p<0. 01 and ?148 kcal/day, NS) in men and women, respectively. A decrease in fat-free mass (FFM) was also observed in women (?1. 8 kg, p<0. 05). The PA-LFD follow-up preserved weight stability at a reduced body weight and caused an additional significant decrease in FM for men (?3. 4 kg, p<0. 05). This part of the intervention also caused an increase in daily RMR for men (134 kcal/day, NS) to the point where this value no longer differed from the pre-energy restriction value. In contrast, RMR was further reduced in women (?200 kcal/day) to the point where it Significantly differed from initial values (p<0. 01). Resting seated heart rate was reduced by the PA-LFD follow-up in men leading it to differ significantly from both pre- and post-energy restriction values (?8. 5 and ?5. 5 bpm, p<0. 01). Discussion: In conclusion, these results suggest that a PA-LFD follow-up has the potential to permit body weight stability and may even accentuate fat loss in the reduced-obese state. Moreover, resting energy expenditure is increased under such conditions in men. These stimulating effects seem to be specific to energy metabolism since seated heart rate was either further reduced or remained stable in response to the PA-LFD follow-up.     

Partial restoration of dietary fat induced metabolic adaptations to training by 7 days of carbohydrate diet.

We tested the hypothesis that a shift to carbohydrate diet after prolonged adaptation to fat diet would lead to decreased glucose uptake and impaired muscle glycogen breakdown during exercise compared with ingestion of a carbohydrate diet all along. We studied 13 untrained men; 7 consumed a high-fat (Fat-CHO; 62% fat, 21% carbohydrate) and 6 a high-carbohydrate diet (CHO; 20% fat, 65% carbohydrate) for 7 wk, and thereafter both groups consumed the carbohydrate diet for an eighth week. Training was performed throughout. After 8 wk, during 60 min of exercise (71 +/- 1% pretraining maximal oxygen uptake) average leg glucose uptake (1.00 +/- 0.07 vs. 1.55 +/- 0.21 mmol/min) was lower (P < 0.05) in Fat-CHO than in CHO. The rate of muscle glycogen breakdown was similar (4.4 +/- 0.5 vs. 4.2 +/- 0.7 mmol. min(-1). kg dry wt(-1)) despite a significantly higher preexercise glycogen concentration (872 +/- 59 vs. 688 +/- 43 mmol/kg dry wt) in Fat-CHO than in CHO. In conclusion, shift to carbohydrate diet after prolonged adaptation to fat diet and training causes increased resting muscle glycogen levels but impaired leg glucose uptake and similar muscle glycogen breakdown, despite higher resting levels, compared with when the carbohydrate diet is consumed throughout training.     

Associations between Apolipoprotein E Genotype, Diet, Body Mass Index, and Serum Lipids in Lithuanian Adult Population

Background

Apolipoprotein E (APOE) polymorphism is associated with lipid levels. Some studies have reported that blood lipid response to diet or obesity varies depending on APOE genotypes. The aim of this study was to assess the effect of APOE genotypes, the intake of saturated fatty acids (SFA), and obesity on serum lipid levels in Lithuanian adult population.

Methodology/Principal Findings

A cross-sectional health survey was carried out in five municipalities of Lithuania. The random sample was obtained from lists of 25–64 year-old inhabitants registered at primary health care centres. The data from 996 subjects (416 men and 580 women) were analysed in this study. Two single-nucleotide polymorphisms (rs429358 and rs7412) were assessed using a real-time polymerase chain reaction. 24-hour recall and food frequency questionnaire were used for evaluation of dietary habits. Serum lipids were determined using enzymatic methods.Men and women with the APOE2 genotype had the lowest level of total cholesterol (TC) (p = 0.002 for men, and p = 0.02 for women) and low-density lipoprotein cholesterol (LDL-C) (p<0.001). Multivariate linear regression analysis showed that age, genotype APOE2, SFA intake, and body mass index (BMI) were significant determinants of TC and LDL-C level (with p values ranging from 0.043 to 0.001). Our data did not reveal any statistically significant interactions between APOE genotype and SFA intake or between APOE genotype and BMI regarding TC and LDL-C level (all p>0.05). However, the predictive power of the regression model for LDL-C improved when gene-BMI interaction and gene-BMI interaction plus gene-nutrient interaction were added (p = 0.04 and p = 0.032 for R² change, respectively).

Conclusions/Significance

APOE genotypes, SFA intake, and obesity were found to be associated with blood lipid levels in Lithuanian adult population. Analysis of gene-diet and gene-obesity interactions did not confirm that the effects of diet and obesity on TC and LDL-C level significantly depended on APOE genotype.     

Comparison of rosuvastatin and atorvastatin for lipid lowering in patients with type 2 diabetes mellitus: results from the URANUS study

Objective

The Use of Rosuvastatin versus Atorvastatin iN type 2 diabetes mellitUS (URANUS) study compared rosuvastatin with atorvastatin for the reduction of low-density lipoprotein cholesterol (LDL-C) in patients with type 2 diabetes.

Methods

After a 6-week dietary run-in, patients aged ≥ 18 years with type 2 diabetes and LDL-C ≥ 3.3 mmol/L were randomised to double-blind treatment with rosuvastatin 10 mg (n = 232) or atorvastatin 10 mg (n = 233) for 4 weeks. Doses were then titrated up to a maximum of rosuvastatin 40 mg or atorvastatin 80 mg over 12 weeks to achieve the 1998 European LDL-C goal (<3.0 mmol/L).

Results

Rosuvastatin reduced LDL-C levels significantly more than atorvastatin during the fixed-dose and titration periods (p < 0.0001). Significantly more patients reached the 1998 LDL-C goal with rosuvastatin 10 mg compared with atorvastatin 10 mg at 4 weeks (81% vs 65%, p < 0.001). At 16 weeks, significantly more patients achieved their LDL-C goal with rosuvastatin compared with atorvastatin (94% vs 88%, p < 0.05) and more patients receiving rosuvastatin remained at their starting dose with reduced requirement for dose titration. At 4 weeks, 65% of rosuvastatin patients had reached their 2003 European LDL-C goal (< 2.5 mmol/L), compared with 33% of atorvastatin patients (p < 0.0001). Both treatments were similarly well tolerated with no unexpected safety concerns.

Conclusion

At the start dose and following dose titration, rosuvastatin was significantly more effective than atorvastatin at reducing LDL-C and achieving European LDL-C goals in patients with type 2 diabetes.     

Diet versus exercise in “the biggest loser” weight loss competition

Background:

Obesity experts have criticized The Biggest Loser television show for its portrayal of an unrealistic intervention that raises false expectations for weight loss. However, the magnitude of the diet and exercise intervention has not been previously quantified.

Design and Methods:

Using a validated computational model of metabolism, I quantified the diet and exercise intervention by integrating data on energy expenditure, body weight and fat mass collected during The Biggest Loser competition.

Results:

Participant body mass index, weight, and percent body fat at baseline were 48.7 ± 10.1 kg/m², 144.9 ± 39.4 kg, and 49 ± 6% (mean ± SD), respectively. During the first phase of the competition when the contestants were isolated in a boot camp environment, the average rate of weight loss was 0.4 ± 0.1 kg/d and decreased to 0.19 ± 0.1 kg/d after returning home. Total weight loss was 58.2 ± 26 kg with 81.6 ± 8.4% coming from body fat. The computer simulations closely matched these data and calculated that average energy intake decreased by 65% during the first phase to 1300 kcal/d while participating in 3.1 h/d of vigorous exercise. After returning home, energy intake increased to 1900 kcal/d and vigorous exercise decreased to 1.1 h/d. Simulation of diet alone resulted in 34 kg of weight loss with 65% coming from body fat, whereas exercise alone resulted in a loss of 27 kg with 102% from fat.

Conclusion:

The intense diet and exercise intervention during The Biggest Loser competition were not sustainable. However, a relatively modest permanent lifestyle intervention of 20% caloric restriction and 20 min/d of vigorous exercise could maintain the massive weight loss.     

Favorable Changes in Lipid Profile: The Effects of Fasting after Ramadan

Aims

We assessed the effect of fasting during Ramadan on blood pressure (BP), body weight, plasma lipid, and lipoprotein variables among healthy normal individuals.

Methods

102 (68% male) multi-ethnic volunteers; mean age ± SD (38.7±10.5 years) were randomly recruited in Al-Ain, United Arab Emirates (UAE), to be investigated before Ramadan, one day after the end of Ramadan, and four weeks after Ramadan. Anthropometric, demographic, fasting plasma total cholesterol (TC), triglyceride (TG), and high density lipoprotein–cholesterol (HDL-C) were measured by standard methods, and Low density lipoprotein-cholesterol (LDL-C) was calculated using Friedewald’s formula.

Results

65 subjects completed the study. We found significant and beneficial changes in systolic blood pressure (SBP), body weight, waist circumference (WC), TG, HDL-C and LDL-C, at the end of Ramadan, but not in TC. Further, there was a progressive and significant increase and decrease in HDL-C and LDL-C levels, respectively, four weeks after Ramadan.

Conclusions

We observed significant improvements in HDL-C, and LDL-C levels even after four weeks post Ramadan. Ramadan-like fasting may be considered for more effective lipid and lipoprotein control.     

Impacts of chronic kidney disease and albuminuria on associations between coronary heart disease and its traditional risk factors in type 2 diabetic patients – the Hong Kong diabetes registry

Background

Glycated haemoglobin (HbA_1c), blood pressure and body mass index (BMI) are risk factors for albuminuria, the latter in turn can lead to hyperlipidaemia. We used novel statistical analyses to examine how albuminuria and chronic kidney disease (CKD) may influence the effects of other risk factors on coronary heart disease (CHD).

Methods

A prospective cohort of 7067 Chinese type 2 diabetic patients without history of CHD enrolled since 1995 were censored on July 30^th, 2005. Cox proportional hazard regression with restricted cubic spline was used to auto-select predictors. Hazard ratio plots were used to examine the risk of CHD. Based on these plots, non-linear risk factors were categorised and the categorised variables were refitted into various Cox models in a stepwise manner to confirm the findings.

Results

Age, male gender, duration of diabetes, spot urinary albumin: creatinine ratio, estimated glomerular filtration rate, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and current smoking status were risk factors of CHD. Linear association between TC and CHD was observed only in patients with albuminuria. Although in general, increased HDL-C was associated with decreased risk of CHD, full-range HDL-C was associated with CHD in an A-shaped manner with a zenith at 1.1 mmol/L. Albuminuria and CKD were the main contributors for the paradoxically positive association between HDL-C and CHD for HDL-C values less than 1.1 mmol/L.

Conclusion

In type 2 diabetes, albuminuria plays a linking role between conventional risk factors and CHD. The onset of CKD changes risk associations between lipids and CHD.     

Low-Carbohydrate Diet and Type 2 Diabetes Risk in Japanese Men and Women: The Japan Public Health Center-Based Prospective Study

ObjectiveEvidence is sparse and contradictory regarding the association between low-carbohydrate diet score and type 2 diabetes risk, and no prospective study examined the association among Asians, who consume greater amount of carbohydrate. We prospectively investigated the association of low-carbohydrate diet score with type 2 diabetes risk.MethodsParticipants were 27,799 men and 36,875 women aged 45–75 years who participated in the second survey of the Japan Public Health Center-Based Prospective Study and who had no history of diabetes. Dietary intake was ascertained by using a validated food-frequency questionnaire, and low-carbohydrate diet score was calculated from total carbohydrate, fat, and protein intake. The scores for high animal protein and fat or for high plant protein and fat were also calculated. Odds ratios of self-reported, physician-diagnosed type 2 diabetes over 5-year were estimated by using logistic regression.ResultsDuring the 5-year period, 1191 new cases of type 2 diabetes were self-reported. Low-carbohydrate diet score for high total protein and fat was significantly associated with a decreased risk of type 2 diabetes in women (P for trend <0.001); the multivariable-adjusted odds ratio of type 2 diabetes for the highest quintile of the score were 0.63 (95% confidence interval 0.46–0.84), compared with those for the lowest quintile. Additional adjustment for dietary glycemic load attenuated the association (odds ratio 0.75, 95% confidence interval 0.45–1.25). When the score separated for animal and for plant protein and fat, the score for high animal protein and fat was inversely associated with type 2 diabetes in women, whereas the score for high plant protein and fat was not associated in both men and women.DiscussionLow-carbohydrate diet was associated with decreased risk of type 2 diabetes in Japanese women and this association may be partly attributable to high intake of white rice. The association for animal-based and plant-based low-carbohydrate diet warrants further investigation.     

Endurance exercise training blunts the deleterious effect of high-fat feeding on whole body efficiency

We recently showed that a week-long, high-fat diet reduced whole body exercise efficiency in sedentary men by >10% (Edwards LM, Murray AJ, Holloway CJ, Carter EE, Kemp GJ, Codreanu I, Brooker H, Tyler DJ, Robbins PA, Clarke K. FASEB J 25: 1088-1096, 2011). To test if a similar dietary regime would blunt whole body efficiency in endurance-trained men and, as a consequence, hinder aerobic exercise performance, 16 endurance-trained men were given a short-term, high-fat (70% kcal from fat) and a moderate carbohydrate (50% kcal from carbohydrate) diet, in random order. Efficiency was assessed during a standardized exercise task on a cycle ergometer, with aerobic performance assessed during a 1-h time trial and mitochondrial function later measured using (31)P-magnetic resonance spectroscopy. The subjects then underwent a 2-wk wash-out period, before the study was repeated with the diets crossed over. Muscle biopsies, for mitochondrial protein analysis, were taken at the start of the study and on the 5th day of each diet. Plasma fatty acids were 60% higher on the high-fat diet compared with moderate carbohydrate diet (P < 0.05). However, there was no change in whole body efficiency and no change in mitochondrial function. Endurance exercise performance was significantly reduced (P < 0.01), most probably due to glycogen depletion. Neither diet led to changes in citrate synthase, ATP synthase, or mitochondrial uncoupling protein 3. We conclude that prior exercise training blunts the deleterious effect of short-term, high-fat feeding on whole body efficiency.     

Decision Tree Analysis of Traditional Risk Factors of Carotid Atherosclerosis and a Cutpoint-Based Prevention Strategy

Background

Reducing the exposure to risk factors for the prevention of cardio-cerebral vascular disease is a crucial issue. Few reports have described practical interventions for preventing cardiovascular disease in different genders and age groups, particularly detailed and specific cutpoint-based prevention strategies.

Methods

We collected the health examination data of 5822 subjects between 20 and 80 years of age. The administration of medical questionnaires and physical examinations and the measurement of blood pressure, fasting plasma glucose (FPG) and blood lipids [total cholesterol (TC), triglycerides (TG), high density lipoprotein–cholesterol (HDL-C), and low density lipoprotein-cholesterol (LDL-C)] were performed by physicians. Carotid ultrasound was performed to examine the carotid intima-media thickness (CIMT), which was defined as carotid atherosclerosis when CIMT ≥0.9 mm. Decision tree analysis was used to screen for the most important risk factors for carotid atherosclerosis and to identify the relevant cutpoints.

Results

In the study population, the incidence of carotid atherosclerosis was 12.20% (men: 14.10%, women: 9.20%). The statistical analysis showed significant differences in carotid atherosclerosis incidence between different genders (P<0.0001) and age groups (P<0.001). The decision tree analysis showed that in men, the most important traditional risk factors for carotid atherosclerosis were TC (cutpoint [CP]: 6.31 mmol/L) between the ages of 20–40 and FPG (CP: 5.79 mmol/L) between the ages of 41–59. By comparison, LDL-C (CP: 4.27 mmol/L) became the major risk factor when FPG ≤5.79 mmol/L. FPG (CP: 5.52 mmol/L) and TG (CP: 1.51 mmol/L) were the most important traditional risk factors for women between 20–40 and 41–59 years of age, respectively.

Conclusion

Traditional risk factors and relevant cutpoints were not identical in different genders and age groups. A specific gender and age group-based cutpoint strategy might contribute to preventing cardiovascular disease.     

高脂血症大鼠血小板活化功能分析

目的分析高脂血症大鼠血小板功能的变化。方法24只Wistar大鼠随机分为正常对照组、高脂血症模型组,4周后检测两组大鼠的血脂：总胆固醇（CHO）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）、高密度脂蛋白胆固醇（HDL-C）水平。应用流式细胞术检测血小板表面a-颗粒膜糖蛋白（CD62P）的表达、酶联免疫法测定血浆中α颗粒膜蛋白．140（GMP140）浓度。所有数据采用Excel软件建库,SPSS11．5统计软件进行分析。结果正常对照组与高脂血症组CHO、TG、LDL-C、HDL-C,CHO分别是1．846mmol／L VS 13．779mmol／L、0．999mmol／L vs 0．746mmol／L、0．164mmol／L vs 10．680mmol／L、0．583mmol／L vs 0．195mmol／L。CD62P、GMP140水平分别为10．089％ vs 25．169％、10．665ng/mL vs 27．045．g／mL。结论高脂血症能够促使血小板活化。