The relationship between the ventilation and lactate thresholds following normal, low and high carbohydrate diets

Five men performed an incremental exercise test following a normal, low and high carbohydrate dietary regimen over a 7-day period, to examine the influence of an altered carbohydrate energy intake on the relationship between the ventilation (VET) and lactate (LaT) thresholds. VET and LaT were determined from the ventilatory equivalents for O2 (VE.VO2(-1) and CO2 (VE.VCO2(-1) and the log-log transformation of the lactate (La) to power output relationship, respectively. The total duration of the incremental exercise test, carbon dioxide output (VCO2), respiratory exchange ratio, blood La values and arterialized venous partial pressure of CO2 (PCO2) were reduced, and VE.VCO2(-1), the slope of the VE-VCO2 relationship, blood beta-hydroxybutyrate and pH were increased during the low carbohydrate trial compared with the other conditions. Total plasma protein and Na+, K+, and Cl- were similar across conditions. LaT and VET were unaffected by the altered proportions of carbohydrate in the diets and occurred at a similar oxygen consumption (mean VO2 across trials was 1.98 L.min-1 for VET and 2.01 L.min-1 for LaT). A significant relationship (r = 0.86) was observed for the VO2 that represented individual VET and LaT values. The increased VE.VCO2(-1) and slope of the VE-VCO2 relationship could be accounted for by the lower PCO2. It is concluded that alterations in carbohydrate energy intake do not produce an uncoupling of VET and LaT as has been reported previously.     

Optimizing healthy gestational weight gain in women at high risk of gestational diabetes: A randomized controlled trial

Objective:

Optimizing gestational weight gain (GWG) in early pregnancy is of clinical and public health importance, especially in higher risk pregnancies.

Design and Methods:

In a robustly designed, randomized controlled trial, 228 pregnant women at risk of developing gestational diabetes mellitus (GDM) were allocated to either control (written health information only) or intervention (four‐session lifestyle program). All women received standard maternal care. Measures were completed at 12‐15 and 26‐28 weeks gestation. Measures included anthropometrics (weight and height), physical activity (pedometer and International Physical Activity Questionnaire), questionnaires (risk perception), and GDM screening.

Results:

The mean (SD) age [31.7 (4.5) and 32.4 (4.7) years] and body mass index [BMI; 30.3 (5.9) and 30.4 (5.6) kg/m²] were similar between control and intervention groups, respectively. By 28 weeks, GWG was significantly different between control and intervention groups [6.9 (3.3) vs. 6.0 (2.8) kg, P < 0.05]. When stratified according to baseline BMI, overweight women in the control group gained significantly more weight compared to overweight women in the intervention group [7.8 (3.4) vs. 6.0 (2.2) kg, P < 0.05], yet in obese women, GWG was similar in both groups. Physical activity levels declined by 28 weeks gestation overall (P < 0.01); however, the intervention group retained a 20% higher step count compared to controls [5,203 (3,368) vs. 4,140 (2,420) steps/day, P < 0.05]. Overall, GDM prevalence was 22%, with a trend toward less cases in the intervention group (P = 0.1).

Conclusions:

Results indicate that a low‐intensity lifestyle intervention, integrated with antenatal care, optimizes healthy GWG and attenuates physical activity decline in early pregnancy. Efficacy in limiting weight gain was greatest in overweight women and in high‐risk ethnically diverse women.     

Circulating monocyte chemoattractant protein-1 in women with gestational diabetes

Monocyte chemoattractant protein 1 (MCP-1) has been implicated as a key factor in the recruitment and activation of peripheral blood leukocytes in atherosclerotic lesions and adipose tissue. Elevated levels of circulating MCP-1 have been found in patients with type 1 and type 2 diabetes, as well as with coronary artery disease. In this study we compared serum MCP-1 concentrations between pregnant women with normal glucose tolerance (NGT), gestational diabetes mellitus (GDM) and non-pregnant healthy women. The group studied consisted of 62 patients with GDM (mean age 30.1 +/- 5.0 years) at 29.0 +/- 3.5 week of gestation, 64 pregnant women with NGT (mean age 30.0 +/- 4.7 years) at 29.2 +/- 2.9 week of gestation and 34 non-pregnant healthy women (mean age 29.8 +/- 4.7 years). Serum MCP-1 concentration was measured using an enzyme - linked immunosorbent assay. Median MCP-1 concentrations did not differ significantly between women with GDM (median 342.3 [interquartile range 267.9-424.4] pg/ml) and NGT (338.0 [274.7-408.2] pg/ml), but were markedly lower than those found in non-pregnant women (485.2 [409.6-642.4] pg/ml, p<0.0001). After adjusting for glucose, the difference between pregnant and non-pregnant women remained highly significant (p<0.0001). In GDM patients MCP-1 levels correlated significantly with fasting glucose (r=0.2665, p=0.0363), insulin (r=0.4330, p=0.0004), HOMA-IR (r=0.4402, p=0.0003), ISQUICKI (r=-0.4402, p=0.0003), HbA1c (r=0.2724, p=0.0322), as well as with prepregnancy and current BMI (r=0.3501, p=0.0057 and r=0.3250, p=0.0106, respectively). Multiple regression analysis revealed that MCP1 concentrations were significantly predicted only by plasma glucose ( beta=0.3489, p=0.00004). Our results suggest that MCP1 levels are decreased in pregnant women, irrespective of their glucose tolerance status.     

Elemental contents in serum of pregnant women with gestational diabetes mellitus

Diabetes mellitus is characterized by hyperglycemia and is closely related to trace elements. Quite a few pregnant women suffer from impaired glucose tolerance (IGT) or gestational diabetes mellitus (GDM). Investigation of the changes of elemental contents in serum of the pregnant women with IGT and GDM is significant in the etiological research and cure of the diseases. In the present work, the elements Cu, Zn, Ca, Sr, Mg, P, Fe, and Al in the serum of pregnant women were determined. The elemental contents in different experimental groups were compared. Also, the correlation between elemental contents and gestational period was observed. The results showed that compared with normal pregnant women, the Cu contents in serum of pregnant women with GDM increased, but Zn contents had a decreasing trend. In addition, for all pregnant women, the Ca contents in serum had an obvious inverse correlation with gestational period.     

Changes of serum selenium in pregnant women with gestational diabetes mellitus

Gestational diabetes is one of the most common diseases in pregnancy. In the present work, the possible relationship between serum selenium concentration and gestational diabetes was investigated. Blood samples of 234 pregnant women were collected, including 98 subjects with impaired glucose tolerance (IGT), 46 subjects with gestational diabetes mellitus (GDM), and 90 normal pregnant women (NPW). An additional 17 samples of normal women of fertile age (NW) were collected for comparison. The hydride generation atomic fluorescence spectrometry was used for selenium determination. The mean serum selenium levels obtained for each group were 0.0741±0.0167 mg/L for NPW, 0.0631±0.0132 mg/L for IGT, 0.0635±0.0120 mg/L for GDM, and 0.108±0.0170 mg/L for NW. Serum selenium levels were significantly lower in pregnant woman with IGT (p<0.001) and GDM (p<0.001) than in NPW. Furthermore, an inverse correlation between the serum selenium concentration and the gestational period was also observed. Selenium supplementation during gestation for pregnant women, especially with IGT and GDM, should be considered.     

Randomised comparison of diets for maintaining obese subjects' weight after major weight loss: ad lib,low fat,high carbohydrate diet v fixed energy intake.

OBJECTIVES: To compare importance of rate of initial weight loss for long term outcome in obese patients and to compare efficacy of two different weight maintenance programmes. DESIGN: Subjects were randomised to either rapid or slow initial weight loss. Completing patients were re-randomised to one year weight maintenance programme of ad lib diet or fixed energy intake diet. Patients were followed up one year later. SETTING: University research department in Copenhagen, Denmark. SUBJECTS: 43 (41 women) obese adults (body mass index 27-40) who were otherwise healthy living in or around Copenhagen. INTERVENTIONS: 8 weeks of low energy diet (2 MJ/day) or 17 weeks of conventional diet (5 MJ/day), both supported by an anorectic compound (ephedrine 20 mg and caffeine 200 mg thrice daily); one year weight maintenance programme of ad lib, low fat, high carbohydrate diet or fixed energy intake diet (< or = 7.8 MJ/day), both with reinforcement sessions 2-3 times monthly. MAIN OUTCOME MEASURES: Mean initial weight loss and proportion of patients maintaining a weight loss of > 5 kg at follow up. RESULTS: Mean initial weight loss was 12.6 kg (95% confidence interval 10.9 to 14.3 kg) in rapid weight loss group and 12.6 (9.9 to 15.3) kg in conventional diet group. Rate of initial weight loss had no effect on weight maintenance after 6 or 12 months of weight maintenance or at follow up. After weight maintenance programme, the ad lib group had maintained 13.2 (8.1 to 18.3) kg of the initial weight loss of 13.5 (11.4 to 15.5) kg, and the fixed energy intake group had maintained 9.7 (6.1 to 13.3) kg of the initial 13.8 (11.8 to 15.7) kg weight loss (group difference 3.5 (-2.4 to 9.3) kg). Regained weight at follow up was greater in fixed energy intake group than in ad lib group (11.3 (7.1 to 15.5) kg v 5.4 (2.3 to 8.6) kg, group difference 5.9 (0.7 to 11.1) kg, P < 0.03). At follow up, 65% of ad lib group and 40% of fixed energy intake group had maintained a weight loss of > 5 kg (P < 0.07). CONCLUSION: Ad lib, low fat, high carbohydrate diet was superior to fixed energy intake for maintaining weight after a major weight loss. The rate of the initial weight loss did not influence long term outcome.     

Circulating pro- and anti-inflammatory cytokines in Polish women with gestational diabetes.

In this study we measured serum concentrations of proinflammatory interleukin-6, interleukin-8, and interleukin-18 as well as anti-inflammatory interleukin-10 in 30 pregnant women with normal glucose tolerance, in 32 women with abnormal results of a 50-g glucose challenge test, and in 57 patients with gestational diabetes mellitus. Patients with gestational diabetes had significantly higher IL-6 (median 1.0 [0.7-1.5] vs. 0.7 [0.4-0.8] pg/ml, p=0.001), IL-8 (2.1 [1.1-4.2] pg/ml vs. 0.7 [0.4-0.9] pg/ml, p<0.0001), and IL-18 (249.3 [188.5-318.7] pg/ml vs. 186.7 [139.9-243.9] pg/ml, p=0.005) as well as lower IL-10 levels than healthy pregnant women (0.6 [0.5-1.5] pg/ml vs. 2.9 [1.8-3.2] pg/ml, p<0.0001). After adjusting for glucose, insulin, and BMI values, the differences in IL-8 and IL-18 became insignificant, whereas the differences in IL-6 and IL-10 levels remained highly significant (p<0.0001). The subjects with abnormal glucose challenge test results had higher IL-6 levels (0.9 [0.7-1.3] pg/ml, p=0.005) and similar levels of other cytokines as compared with the women with normal glucose tolerance. Our results suggest an impaired balance between circulating pro- and anti-inflammatory cytokines in patients with gestational diabetes; however, a significant contribution of maternal obesity to the increased levels of IL-8 and IL-18 should be underlined.     

Immunological titration of rat liver glucose-6-phosphate dehydrogenase from animals fed high and low carbohydrate diets.

Recent work (Hizi and Yagil [1974] Eur. J. Biochem. $\text{45}$: 211–221, and Kelly $\text{et. al.}$ [1975] Fed. Proc. $\text{34}$: 881) suggests that the marked increase in rat liver glucose-6-phosphate dehydrogenase activity which is observed upon feeding an animal a high carbohydrate diet does not involve an increase in the total amount of enzyme present. In contrast, the data presented herein involving immunological titrations of rat liver glucose-6-phosphate dehydrogenase indicates that the increase in enzyme activity resulting from feeding a high carbohydrate diet does involve an increase in the total amount of enzyme present.     

Lymphocyte subsets and cytokines in women with gestational diabetes mellitus and their newborn

This study aimed to identify potential immunological markers for predicting type 1 diabetes in patients with gestational diabetes mellitus (GDM) and any immunological impairment in their newborn. In 62 GDM patients and 74 women with normal glucose tolerance (NGT), and their babies, we assessed total lymphocytes, T lymphocyte subsets CD3 and CD8 expressing T cell receptor (TCR) alpha/beta or gamma/delta, CD16 and CD19, pancreatic autoantibodies and cytokines (IL-5, IL-2, soluble receptor IL-2). At delivery, umbilical cord blood samples were taken for lymphocyte subpopulations and cytokine measurements. GDM mothers had higher levels of total lymphocytes, CD8 expressing TCR gamma/delta, and lower levels of CD3 expressing TCR alpha/beta than NGT controls. Insulin-treated GDM mothers had lower CD4 and CD4/CD8 ratios, and higher CD8 and IL-5 than diet-treated GDM or controls. Five women were positive for pancreatic autoantibodies, with lower CD4 (p<0.01) and CD4/CD8 ratios (p<0.05), and higher CD8 (p<0.03) and CD19 than GDM and control mothers negative for autoantibodies. GDM newborn had higher CD8 gamma/delta and lower CD16 than NGT babies. There were no significant differences in TNF-alpha concentrations in the cord blood obtained from the GDM and NGT newborn. In conclusion, GDM women and their newborn have lymphocyte subset impairments, which are more important in patients positive for autoantibodies and/or treated with insulin.     

Cytokine profile, metabolic syndrome and cardiovascular disease risk in women with late-onset gestational diabetes mellitus

Inflammation is an important component of the metabolic syndrome (MetS) which could be the link between the metabolic and the cardiovascular consequences of this condition. Gestational diabetes mellitus (GDM) has been recognized as a significant risk factor for MetS and an inflammation component has been described in this disease. The aim of the study was to evaluate the relationships between cytokine concentrations, components of MetS and cardiovascular risk markers in women with late-onset GDM. Women (n=63) with late-onset GDM and 63 controls were enrolled. Clinical variables, and obstetrics and perinatal outcomes were recorded. Relationships between cytokines (TNF-α, leptin, IL6, adiponectin) and endothelial injury markers (VCAM, ICAM and selectine) were analyzed. Control vs. patient data indicated: pre-gestational body mass index (BMI) 23.46±3.73 vs. 26.97±5.07kg/m(2) (p=0.001); TNF-α 2.2±0.8 vs. 3.1±1.5pg/mL (p=0.002); leptin 18714.78±8859.08 vs. 27365.79±16209.67pg/mL (p=0.001); adiponectin 162.42±34.19 vs. 141.54±41.33ng/mL (p=0.04). Multivariate analyses showed that adiponectin had a protective effect (OR=0.9; p=0.02) and BMI carried a significant risk (OR=8.4; p=0.01) for GDM. No differences were found in endothelial injury markers. In conclusion, the cytokine profile in women with late-onset GDM is characterized by high concentrations of TNF-α and leptin and low adiponectin. This profile is related, in large extent, to an increased pregravid BMI which, potentially, may be linked to the future development of both metabolic and cardiovascular disease.     

Echinacea purpurea L. in children: safety, tolerability, compliance, and clinical effectiveness in upper respiratory tract infections

Echinacea purpurea (L.) Moench was mistakenly taken from North America to Germany in 1939 where it was cultivated and various extractions were prepared and subsequently used to treat upper respiratory tract infections. Parents often administer Echinacea to their children, but safety data on the use of Echinacea in Canadian children is lacking. A screening history, physical examination, and daily record of symptoms from an initial visit through to a the follow-up visit 13 days later were used to increase patient safety. Each subject was administered an aerial part Echinacea extract. The dose was based on age (2.5 mL three times per day for children aged 2-5 years, and 5 mL two times per day for children aged 6-12 years) and administered for 10 days in an open-label trial. A rating scale was used to measure tolerance to the treatment. We assessed the safety and compliance of use of the Echinacea extract by measuring the amount of extract returned at the end of the study, having the parents complete and return a daily symptom diary, and recording the subjects' use of other natural health products or medications during the trial. Clinical effectiveness of the Echinacea extract could not be accurately assessed because of the small trial size and because the extract had been administered when some of the subjects had an upper respiratory tract infection that had begun 1 or more days prior to the study; however, each subject's symptoms improved. No allergic or adverse reaction occurred and no safety issues arose.