Epidemiology of hyperuricemia in the elderly

BACKGROUND: Our study used data collected in Chung-Hsing Village to evaluate the relationship between hyperuricemia and the cardiovascular risk factors and the socio-demographic factors in the elderly in May 1998. METHODS: All individuals aged 65 and over were studied. A total of 1093 subjects, out of 1774 registered residents, were contacted by face-to-face interview. The response rate was 61.6 percent. However only 586 respondents had blood tests and completed questionnaires. Analysis in this study was based on these 586 subjects. To study the significant correlates of hyperuricemia, t- test, two-way ANOVA, chi-square test and multivariate logistic regression were used. RESULTS: Our results showed that 66 percent were men and 34 percent were women. The mean age was 73.1+/-5.3 years. The proportions of hyperuricemia were 57.3 percent in men and 40.9 percent in women (p < .01). In chi-square test, hypercholesterolemia, hypertriglyceridemia, renal function impairment, retirement status and marital status were related to hyperuricemia. After controlling the other covariates, the multivariate logistic regression analysis showed that the significant related factors of hyperuricemia were hypercholesterolemia, hypertriglyceridemia, and renal function impairment. CONCLUSIONS: Hyperuricemia is often found in the elderly. Hyperuricemia is more common in elderly men than in elderly women. A large-scale investigation will be suggested in the future to address causal-effect issues between hyperuricemia and hypercholesterolemia, hypertriglyceridemia, or renalfunction impairment.     

Epidemiology of obesity in elderly people

Our study used data collected at Chung-Shing-Shin-Tseun community in Taiwan in May 1998 to evaluate the relationship between obesity and the cardiovascular and sociodemographic risk factors in elderly people. Individuals aged 65 and over were recruited as study subjects. A total of 1093 persons, out of 1774 registered residents, were contacted in face-to-face interview. The response rate was 61.6 percent. However only 586 respondents took blood tests and completed questionnaires. Analysis in this study was based on these 586 subjects. The chi-square analysis and multivariate logistic regression were used to study the significant correlates of obesity. Our results showed that 66 percent were men and 34 percent were women. The mean age was 73.1 +/- 5.3 years. The overweight proportions were 24.8 percent in elderly men and 29.7 percent in elderly women. The obesity proportions were 12.7 percent in elderly men and 11.5 percent in elderly women. After controlling the other covariates, the multivariate logistic regression analysis showed that overweight and obesity were associated with hypertension, hypertriglyceridemia, and hyperglycemia. In conclusions, the prevalence of overweight and obesity is high in Taiwanese elderly people. Thus, it is necessary to evaluate other metabolic disorders if one metabolic abnormality is observed.     

Hypertension and its related factors in Taiwanese elderly people

BACKGROUND: Our study used data collected in Chung-Hsing Village in May 1998 to evaluate the prevalence of hypertension and its correlates in Taiwanese elderly people. METHODS: All of individuals aged 65 and over were recruited as study subjects. A total of 1,093 persons, out of 1,774 registered residents, were contacted by face-to-face interview The response rate was 61.6 percent. However, only 586 respondents had blood tests and completed questionnaires. Analysis in this study was based on these 586 subjects. In order to study the significant correlates of hypertension, the t-test, chi-square analysis, and multivariate logistic regression were used. RESULTS: Our results showed that 66 percent were men and 34 percent were women. The mean age was 73.1 +/- 5.3 years. The proportions of hypertension were 53.09 percent in men and 56.06 percent in women (p > 0.05). After controlling the other covariates, the multivariate logistic regression analysis showed that the significant related factors of hypertension were obesity (OR = 1.88, 95 percent CI = 1.06-3.34, p < 0.05) and renalfunction impairment (OR = 1.69, 95 percent CI = 1.02-2.80, p < 0.05). CONCLUSIONS: The prevalence of hypertension was high in elderly people. Hypertension is significantly associated with obesity and renalfunction impairment in elderly people.     

Epidemiology of serum aminotransferase activities in the elderly.

BACKGROUND: Our study used data collected in Chung-Hsing Village in May 1998 to explore the distribution of serum aminotransferase activities and the relationship between aminotransferase and its related factors in the elderly. METHODS: All individuals aged 65 and over were recruited as study subjects. A total of 1093 persons, out of 1774 registered residents, were contacted by face-to-face interview. The response rate was 61.6 percent. However, only 586 subjects had blood tests and completed questionnaires. Analysis in this study was based on these 586 subjects. In order to study the significant related factors of abnormal aminotransferase activities, the t-test, ANOVA, chi-square analysis, and multivariate logistic regression were used. RESULTS: There were 66 percent men and 34 percent women. The mean age was 73.1 +/- 5.3 years. The mean values of aspartate aminotransferase (AST) were 29.3 +/- 14.5 u/l in men and 27.8 +/- 10.7 u/l in women (p > .05). The mean values of alanine aminotransferase (ALT) were 30.9 +/- 25.2 u/l in men and 26.3 +/- 12.6 u/l in women (p < .01). The abnormality rates of AST (> or = 40 u/l) were 10.5 percent in men and 12.2 percent in women (p > .05). The abnormality rates of ALT (> or = 40 u/l) were 16.7 percent in men and 12.6 percent in women (p > .05). After controlling for the other covariates, the multivariate logistic regression analysis showed that the significant related factor of abnormal AST was retirement status (odds ratio 4.4; 95 percent confidence interval = 1.5-13.3; p < .01). The significant related factors of abnormal ALT were obesity (odds ratio = 2.2; 95 percent confidence interval = 1.1-4.2; p < .05) and hypertriglyceridemia (odds ratio = 2.7; 95 percent confidence interval = 1.5-4.9; p < .01). CONCLUSIONS: We raise the hypothesis that evidence of liver disease with abnormal ALT may co-vary with other indicators of chronic diseases. A large-scale investigation will be suggested in the future to demonstrate the causal-effect issue between abnormal ALT and obesity or hypertriglyceridemia.     

Comparison of Various Anthropometric and Body Fat Indices in Identifying Cardiometabolic Disturbances in Chinese Men and Women

Background

Although many adiposity indices may be used to predict obesity-related health risks, uncertainty remains over which of them performs best.

Objective

This study compared the predictive capability of direct and indirect adiposity measures in identifying people at higher risk of metabolic abnormalities.

Methods

This population-based cross-sectional study recruited 2780 women and 1160 men. Body weight and height, waist circumference (WC), and hip circumference (HC) were measured and body mass index (BMI), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) were calculated. Body fat (and percentage of fat) over the whole body and the trunk were determined by bioelectrical impedance analysis (BIA). Blood pressure, fasting lipid profiles, and glucose and urine acid levels were assessed.

Results

In women, the ROC and the multivariate logistic regression analyses both showed that WHtR consistently had the best performance in identifying hypertension, dyslipidemia, hyperuricemia, diabetes/IFG, and metabolic syndrome (MetS). In men, the ROC analysis showed that WHtR was the best predictor of hypertension, WHtR and WC were equally good predictors of dyslipidemia and MetS, and WHtR was the second-best predictor of hyperuricemia and diabetes/IFG. The multivariate logistic regression also found WHtR to be superior in discriminating between MetS, diabetes/IFG, and dyslipidemia while BMI performed better in predicting hypertension and hyperuricemia in men. The BIA-derived indices were the second-worst predictors for all of the endpoints, and HC was the worst.

Conclusion

WHtR was the best predictor of various metabolic abnormalities. BMI may be used as an alternative measure of obesity for identifying hypertension in both sexes.     

Reproducibility of an oral fat tolerance test is influenced by phase of menstrual cycle.

Knowledge of the reproducibility of oral fat tolerance tests is important for experimental design and data interpretation. In this study, seven normolipidaemic men underwent two fat tolerance tests (blood taken fasting and for six hours after a meal containing 1.2 g fat, 1.2 g carbohydrate per kg body mass) with an interval of one week. Eleven normolipidaemic women underwent two fat tolerance tests--one during the follicular phase of the menstrual cycle, the other during the mid-luteal phase. Dietary intake was controlled for two days and subjects refrained from exercise for three days before each test. There was no significant difference in postprandial triglyceride responses between the two tests in the men (10.20 +/- 3.45 mmol/l.h vs. 9.68 +/- 2.77 mmol/l.h, NS) (mean +/- SD); intraclass correlation coefficient between the two tests was 0.93, and within-subject coefficient of variation was 10.1 %. In the women, the postprandial triglyceride response was lower in the luteal phase (6.75 +/- 1.83 mmol/l.h) than in the follicular phase (8.36 +/- 3.71 mmol/l.h) (p = 0.05), intraclass correlation was 0.65 and within-subject coefficient of variation was 23.2 %. These results suggest that, with adequate control of preceding lifestyle, reproducibility of postprandial triglyceride responses is high in men, but menstrual phase should be taken into consideration when studying these responses in women.     

Familial defective apolipoprotein B-100: a lesson from homozygous and heterozygous patients

Familial defective apolipoprotein B-100 (FDB) is a genetic disorder caused by a substitution of glutamine for arginine at residue 3500 of the apolipoprotein B-100 molecule. We have identified 23 heterozygotes and one homozygote for FDB (frequency 1:20) in a group of 510 patients with hypercholesterolemia. Mean age of the patients (18 females and 6 males) was 46 years. The diagnosis of FDB was based on point mutation PCR analysis of exon 26 of the apo B gene. Plasma lipids in heterozygous patients were: total cholesterol 8.76+/-1.2 mmol/l, triglycerides 1.42+/-0.5 mmol/l, HDL-cholesterol 1.43+/-0.3 mmol/l, LDL-cholesterol 6.69+/-1.2 mmol/l, apoB 1.69+/-0.4 g/l, Lp(a) 0.26+/-0.2 g/l. The most frequent apoE genotype was 3/3 (19 patients), apoE 3/4 genotype was found in 3 patients and one person had apoE 2/3. Xanthelasma palpebrarum was present in 4 patients and tendon xanthomas in 3 patients including the homozygote. Premature manifestation of coronary heart disease was revealed in 3 patients. Sixteen patients were treated with statins, a combination of statin and resin was used in 2 patients (including the homozygote), whereas six patients were treated with the diet only. We conclude that although the plasma lipid levels of total and LDL cholesterol in FDB patients are lower than in patients with familial hypercholesterolemia, the patients with FDB suffer from premature atherosclerosis. The therapeutic approach to FDB individuals and patients with familial hypercholesterolemia is very similar.     

Effects of a combination of recombinant human growth hormone with metformin on glucose metabolism and body composition in patients with metabolic syndrome.

Abdominal obesity and insulin resistance are central findings in metabolic syndrome. Since treatment with recombinant human growth hormone (rhGH) can reduce body fat mass in patients with organic GH deficiency, rhGH therapy may also have favourable effects on patients with metabolic syndrome. However, due to the highly increased risk for type 2 diabetes in these patients, strategies are needed to reduce the antagonistic effect of rhGH against insulin. We conducted a 18-month randomised, double-blind, placebo-controlled study to assess the effect of rhGH in combination with metformin (Met) in patients with metabolic syndrome. 25 obese men (55 +/- 6 years, BMI 33.4 +/- 2.9 kg/m (2)) with mildly elevated fasting plasma glucose (FPG) levels at screening (6.1-8.0 mmol/l) were included. All patients received metformin (850 mg twice daily) either alone or in combination with rhGH (daily dose 9.5 microg/kg body weight). An oGTT was performed at baseline, after 6 weeks, and after 3, 6, 12, and 18 months of therapy. Glucose disposal rate (GDR) was measured by euglycemic hyperinsulinemic clamp at 0 and 18 months and body composition was measured by DEXA every 6 months. In the Met + GH group, IGF-I increased from 146 +/- 56 microg/l to 373 +/- 111 microg/l (mean +/- SD) after 3 months and remained stable after that. BMI did not change significantly in either group during the study. Total body fat decreased by -4.3 +/- 5.4 kg in the Met + GH group and by -2.7 +/- 2.9 kg in the Met + Placebo group (differences between the two groups: p = n. s.). Waist circumference decreased in both groups (Met + GH: 118 +/- 8 cm at baseline, 112 +/- 10 cm after 18 months; Met + Placebo: 114 +/- 7 cm vs. 109 +/- 8 cm; differences between the two groups: p = 0.096). In the Met + GH group, FPG increased significantly after 6 months (5.9 +/- 0.7 vs. 6.7 +/- 0.4 mmol/l; p = 0.005), but subsequently decreased to baseline levels (18 months: 5.8 +/- 0.2 mmol/l). FPG remained stable in the Met + Placebo group until 12 months had elapsed, and then slightly decreased (baseline: 6.2 +/- 0.3, 18 months: 5.5 +/- 0.6 mmol/l, p = 0.02). No significant changes were seen in either group regarding glucose and insulin AUC during oGTT or HbA (1c) levels. GDR at 18 months increased by 20 +/- 39% in Met + GH-group and decreased by -11 +/- 25% in the Met + Placebo group (differences between the two groups: p = 0.07). In conclusion, treatment of patients with metabolic syndrome and elevated FPG levels did not cause sustained negative effects on glucose metabolism or insulin sensitivity if given in combination with metformin. However, since our data did not show significant differences between the two treatment groups with respect to body composition or lipid metabolism, future studies including larger numbers of patients will have to clarify whether the positive effects of rhGH on cardiovascular risk factors that have been shown in patients with GH deficiency are also present in patients with metabolic syndrome, and are additive to the effects of metformin.     

Coenzyme Q improves LDL resistance to ex vivo oxidation but does not enhance endothelial function in hypercholesterolemic young adults

Oxidative modification of low-density lipoprotein (LDL) may cause arterial endothelial dysfunction in hyperlipidemic subjects. Antioxidants can protect LDL from oxidation and therefore improve endothelial function. Dietary supplementation with coenzyme Q (CoQ(10)) raises its level within LDL, which may subsequently become more resistant to oxidation. Therefore, the aim of this study was to assess whether oral supplementation of CoQ(10) (50 mg three times daily) is effective in reducing ex vivo LDL oxidizability and in improving vascular endothelial function. Twelve nonsmoking healthy adults with hypercholesterolemia (age 34+/-10 years, nine women and three men, total cholesterol 7.4+/-1.1 mmol/l) and endothelial dysfunction (below population mean) at baseline were randomized to receive CoQ(10) or matching placebo in a double-blind crossover study (active/placebo phase 4 weeks, washout 4 weeks). Flow-mediated (FMD, endothelium-dependent) and nitrate-mediated (NMD, smooth muscle-dependent) arterial dilatation were measured by high-resolution ultrasound. CoQ(10) treatment increased plasma CoQ(10) levels from 1.1 +/-0.5 to 5.0+/-2.8 micromol/l (p =.009) but had no significant effect on FMD (4.3+/-2.4 to 5.1+/-3.6 %, p =.99), NMD (21.6+/-6.1 to 20.7+/-7.8 %, p = .38) or serum LDL-cholesterol levels (p = .51). Four subjects were selected randomly for detailed analysis of LDL oxidizability using aqueous peroxyl radicals as the oxidant. In this subgroup, CoQ(10) supplementation significantly increased the time for CoQ(10)H(2) depletion upon oxidant exposure of LDL by 41+/-19 min (p = .04) and decreased the extent of lipid hydroperoxide accumulation after 2 hours by 50+/-37 micromol/l (p =.04). We conclude that dietary supplementation with CoQ(10) decreases ex-vivo LDL oxidizability but has no significant effect on arterial endothelial function in patients with moderate hypercholesterolemia.     

Gender differences in plasma levels of lipoprotein (a) in patients with angiographically proven coronary artery disease

The objective of the study was to assess the association between plasma levels of lipoprotein(a) [Lp(a)] and the presence of angiographically defined coronary artery disease (aCAD). Patients (346 men and 184 women) undergoing selective coronary angiography (SCA) were classified into groups with positive [aCAD(+)] and negative [aCAD(-)] findings and their age, body mass index (BMI), waist circumference, blood pressure, smoking, plasma total, LDL-, HDL-cholesterol (TC, LDL-C, HDL-C), triglycerides (TG), apolipoprotein B (apoB), Log(TG/HDL-C) and TC/HDL-C were determined. Concentration of plasma Lp(a) was estimated using the commercial solid phase two-side immunoradiometric assay of apolipoprotein apo(a). The plasma Lp(a) was significantly higher in both women and men with aCAD(+) compared to those with aCAD(-). While there was no significant difference in the Lp(a) level between men and women with aCAD(-) (median 138 vs. 145 units/l), the women with aCAD(+) had almost twice as high Lp(a) levels as men (median 442 vs. 274 units/l, p<0.001). Women with aCAD(+) had also significantly lower HDL cholesterol levels (1.09 vs. 1.20 mmol/l, p<0.05), higher triglycerides (1.82 vs. 1.46 mmol/l, p<0.05) and Log(TG/HDL-C) than women with aCAD(-). The differences in Lp(a) between positive and negative findings remained highly significant (p<0.001 in women, p<0.05 in men) after the adjustment for age, plasma HDL- and LDL-cholesterol and triglycerides in logistic regression analyses. In logistic regression model the Lp(a) and Log(TG/HDL-C) and smoking in women but smoking and age in men were the most powerful predictors of positive aCAD findings. Our findings suggest that Lp(a) is more strongly associated with aCAD+ in women than in men.     

The lipid accumulation product is associated with increased mortality in normal weight postmenopausal women

Lipid accumulation product (LAP) is an emerging cardiovascular risk factor, which is calculated from waist circumference (WC) and triglyceride (TG) levels. The aim of this study was to elucidate the relationship between LAP and cardiovascular mortality as well as the presence of type 2 diabetes with respect to gender-specific differences. We determined WC and fasting TG levels and the cardiovascular and metabolic phenotypes coronary artery disease (CAD), hypertension, metabolic syndrome, and diabetes mellitus in 2,279 men and 875 postmenopausal women who were routinely referred to coronary angiography. The LAP was calculated as (WC (cm)--65) × (TG (mmol/l)) for men and as (WC (cm)--58) × (TG (mmol/l)) for women. LAP levels were independently associated with congestive heart failure mortality in all postmenopausal women and with all-cause mortality in diabetic postmenopausal women but not in men. Multivariable-adjusted hazard ratios (with 95% confidence intervals) for all-cause, cardiovascular, and congestive heart failure mortality in the third compared to the first LAP tertile were 4.28 (1.94-9.44; P < 0.001), 3.47 (1.28-9.40; P = 0.015), and 10.77 (1.21-95.88; P = 0.033), respectively, in normal weight postmenopausal women, whereas no significant associations were found in men. LAP levels were highly associated with type 2 diabetes in all subjects, postmenopausal women, and men. High LAP values are predictive of mortality independently of other cardiovascular risk factors in normal weight and diabetic postmenopausal women but not in men. Type 2 diabetes (T2DM) was highly associated with LAP in women and men. Our study validates an inexpensive and simple risk profiling that may allow identifying postmenopausal women at high cardiovascular risk.     

Hyperlipidemia is associated with altered levels of insulin-like growth factor-I

Previous studies revealed altered levels of the circulating insulin-like growth factor-I (IGF-I) and of its binding protein-3 (IGFBP-3) in subjects with coronary atherosclerosis, metabolic syndrome and premature atherosclerosis. Hyperlipidemia is a powerful risk factor of atherosclerosis. We expected IGF-I and IGFBP-3 alterations in subjects with moderate/severe hyperlipidemia but without any clinical manifestation of atherosclerosis. Total IGF-I and IGFBP-3 were assessed in 56 patients with mixed hyperlipidemia (MHL; cholesterol >6.0 mmol/l, triglycerides >2.0 mmol/l), in 33 patients with isolated hypercholesterolemia (IHC; cholesterol >6.0 mmol/l, triglycerides <2.0 mmol/l), and in 29 healthy controls (cholesterol<6.0 mmol/l, triglycerides<2.0 mmol/l). The molar ratio of IGF-I/IGFBP-3 was used as a measure of free IGF-I. IHC subjects differed from controls by lower total IGF-I (164+/-60 vs. 209+/-73 ng/ml, p=0.01) and IGF-I /IGFBP-3 ratio (0.14+/-0.05 vs. 0.17+/-0.04, p=0.04). Compared to controls, MHL subjects had lower total IGF-I (153+/-54 ng/ml, p=0.0002) and IGFBP-3 (2.8+/-0.6 mg/ml, p<0.0001), but higher IGF-I/IGFBP-3 ratio (0.25+/-0.06, p<0.0001). Differences remained significant after the adjustment for clinical and biochemical covariates, except for triglycerides. Patients with both IHC and MHL have lower total IGF-I compared to controls. The mechanism is presumably different in IHC and MHL. Because of prominent reduction of IGFBP-3 in patients with MHL, they have reduced total IGF-I despite the actual elevation IGF-I/IGFBP-3 ratio as a surrogate of free IGF-I.     

Human hepatic low-density lipoprotein receptors: associations of receptor activities in vitro with plasma lipid and apolipoprotein concentrations in vivo

The relationships of plasma lipid and apolipoprotein (apo) concentrations to hepatic low-density lipoprotein (LDL) receptor activity were examined in 21 subjects (16 females, 5 males), who were undergoing laparotomy for non-neoplastic disease (cholecystectomy in 16). None had familial hypercholesterolemia, or renal, endocrine or hepatic disease. Ages were 37-77 years (mean, 58 years), plasma cholesterol concentrations 4.09-6.72 mmol/l (5.38) and plasma triacylglycerol concentrations 0.75-2.35 mmol/l (1.36). Receptor activity was quantified in vitro as the total saturable binding and EDTA-suppressible binding (representing apoB,E receptors) of 125I-labelled human LDL (15 micrograms protein/ml) by liver homogenate at 37 degrees C. There were no significant differences between men and women in 125I-labeled LDL binding. In the pooled data, EDTA-suppressible binding averaged 50 ng 125I-LDL protein/mg cell protein (S.D., 15). Total saturable binding averaged 2-fold greater (mean, 101 ng/mg; S.D., 32). Plasma cholesterol, LDL cholesterol and apoB concentrations were negative functions of both EDTA-suppressible binding and total saturable binding, but the correlations with EDTA-suppressible binding were stronger (cholesterol: r = -0.59, P less than 0.01; LDL cholesterol: r = -0.48, P less than 0.05; apoB: r = -0.61, P less than 0.01). Plasma triacylglycerol, high-density lipoprotein cholesterol and apoA-I concentrations were not related to either measure of receptor activity. These results provide evidence that the activity of apoB,E receptors in the liver is a major determinant of the plasma LDL concentration in middle-aged and elderly humans.     

A single bout of exercise influences natural killer cells in elderly women, especially those who are habitually active

The purpose of our study was to examine the effects of a single exercise bout on the natural killer (NK) cell count and activity in physically active elderly people, sedentary elderly people, and sedentary young people. Eight elderly women who trained by walking (age, 64 +/- 1 years; Vo(2peak), 32.2 +/- 1.1 ml.kg(-1).min(-1)), 8 age-matched untrained women (63 +/- 1 years, 28.8 +/- 1.0 ml.kg(-1).min(-1)), and 8 young untrained women (25 +/- 1 years, 37.6 +/- 1.6 ml.kg(-1).min(-1)) were studied. Blood samples were taken before, immediately after, and 2 hours after a 30-minute bout of exercise at an intensity equivalent to 70-75% of Vo(2peak). Peripheral blood mononuclear cells were isolated and the NK cell count and activity were analyzed. The NK cell count of the elderly sedentary group immediately after exercise was significantly higher than those of the elderly women who walked and young sedentary women, whereas no significant interaction was detected in NK cell activity and NK cell activity per cell number among the 3 groups. Consequently, an intrinsic defect in the cytotoxic ability of NK cells appeared in sedentary elderly people but not in active elderly people who perform habitual exercise.     

Homocysteine and cystatin C level changes in haemodialysed patients and connection with cerebro- and cardiovascular complications

Plasma homocysteine and Cystatin C levels of 360 chronic haemodialysed patients were measured in fasting (191 men, mean age: 55.5 years; and 169 women, mean: 62.9 years). The patients were divided into subgroups: diabetes mellitus (34 men and 38 women 7 vs 8 IDDM). obliterative arteriosclerosis (68 men and 61 women), cardiovascular complications (75 men and 84 women) and stroke (16 men and 12 women), and after renal transplantation in chronic rejection (15 men and 5 female). Homocysteine was determined by IMx analyser from Abbott by FPIA method. Immunoturbidimetric method was used for quantification of Cystatin C (PETIA). The lowest Cystatin C concentration was found in diabetic patients (4.35 +/- 0.15 mg/l in men and 3.18 +/- 1.77 mg/l in women) and the highest one occurred in anuric and bilateral nephrectomised and transplanted chronic rejected patients (6.075 mg/l in men and 6.35 mg/l in women: p<0.001). The homocysteine levels (24.98 +/- 2.94 micromol/l in men and 23.88 +/- 1.76 micromol/l in women) exceeded the upper limit of reference range (<15.0 micromol/l). There was a significant difference in favour of subgroup of cardiovascular (27.25 micromol/l in men and 26.87 micromol/l in women) and stroke patients (27.16 micromol/l in men and 30.76 micromol/l in women p<0.001). Elevated levels were found in chronic rejected patients with accelerated arteriosclerotic events (25.94 micromol/l in men and 27.43 micromol/l in women). Good positive linear correlation was found between serum homocysteine and Cystatin C levels (r=0.2393 and 0.2252). The authors demonstrated hyperhomocysteinaemia associated with high Cystatin C concentration in four subgroups of haemodialysed patients (obliterative and accelerated arteriosclerosis, cardiovascular disease, and cerebrovascular complications and stroke).     

23Na NMR evaluation of human erythrocytes Na+/K+/CL-cotransport. A study in elderly hypertensives.

The behaviour of sodium transport systems across the cell membrane has been poorly investigated in elderly hypertension. Sodium efflux driven by Na+/K+/Cl-cotransport activity was therefore investigated (using a novel NMR-spectroscopy method) in 5 elderly hypertensive males (mean age 78 +/- 5 years) and 5 normotensive controls (mean age 79 +/- 3 years). In order to exclude any change in cotransport activity secondary to metabolic abnormalities, both patients and controls were non-obese and had normal glucose and lipid metabolisms. The Na+/K+/Cl-cotransport evaluation was performed after three months of pharmacological wash-out, under a diet containing 120 mEq of Na+/day. The resulting data showed that Na+ efflux due to outward Na+/K+/Cl-cotransport was higher in hypertensive group than in the normotensive one (0.50 +/- 0.10 mmol Na+/l cells/hr. vs 0.33 +/- 0.03 mmol Na+/l cells/hr., respectively, p < 0.05). Intracellular Na+ content was similar in both groups. At variance with previous data from the literature, our findings indicate that the Na+/K+/Cl-cotransport activity is elevated in elderly hypertensives.     

A novel allele in the promoter of the hepatic lipase is associated with increased concentration of HDL-C and decreased promoter activity

Hepatic lipase (HL) is a lipolytic enzyme involved in the metabolism of plasma lipoproteins, especially HDLs. Association of the polymorphisms in the promoter region of the LIPC gene to post-heparin plasma HL activity and the plasma HDL-C concentration has been investigated thoroughly, but to date little is known about this in the Chinese. In the present study, we analyzed the polymorphisms in the promoter region of LIPC gene in Chinese patients with coronary artery disease (CAD) using denaturing high performance liquid chromatography (DHPLC) and DNA sequencing. As the result, a novel single nucleotide polymorphism -586T-to-C was identified and no linkage of this variant with other polymorphisms in the promoter was found. Compared with the nonsymptomatic control subjects, excess of carriers of the -586T/C substitution were detected in the CAD patients (43% vs. 31%, chi(2) = 4.597, degree of freedom = 2, P = 0.032).The -586C allele carriers in the CAD patients had a significantly higher HDL-C level than the noncarriers (1.13 +/- 0.24 mmol/l vs. 0.91 +/- 0.14 mmol/l, P < 0.05). To test the functionality of this substitution, luciferase-reporter assays was performed in HepG2 cells. Promoter activity of the -586C construct was decreased 2-fold than the -586T construct. Our studies suggest that a T-to-C substitution at -586 of the LIPC promoter is associated with a lowered HL activity and that this variation may contribute to the increased plasma HDL-C concentration in the Chinese.     

Glycogen loading alters muscle glycogen resynthesis after exercise.

This study compared muscle glycogen recovery after depletion of approximately 50 mmol/l (DeltaGly) from normal (Nor) resting levels (63.2 +/- 2.8 mmol/l) with recovery after depletion of approximately 50 mmol/l from a glycogen-loaded (GL) state (99.3 +/- 4.0 mmol/l) in 12 healthy, untrained subjects (5 men, 7 women). To glycogen load, a 7-day carbohydrate-loading protocol increased muscle glycogen 1.6 +/- 0.2-fold (P < or = 0.01). GL subjects then performed plantar flexion (single-leg toe raises) at 50 +/- 3% of maximum voluntary contraction (MVC) to yield DeltaGly = 48.0 +/- 1.3 mmol/l. The Nor trial, performed on a separate occasion, yielded DeltaGly = 47.5 +/- 4.5 mmol/l. Interleaved natural abundance (13)C-(31)P-NMR spectra were acquired and quantified before exercise and during 5 h of recovery immediately after exercise. During the initial 15 min after exercise, glycogen recovery in the GL trial was rapid (32.9 +/- 8.9 mmol. l(-1). h(-1)) compared with the Nor trial (15.9 +/- 6.9 mmol. l(-1). h(-1)). During the next 45 min, GL glycogen synthesis was not as rapid as in the Nor trial (0.9 +/- 2.5 mmol. l(-1). h(-1) for GL; 14.7 +/- 3.0 mmol. l(-1). h(-1) for Nor; P < or = 0.005) despite similar glucose 6-phosphate levels. During extended recovery (60-300 min), reduced GL recovery rates continued (1.3 +/- 0.5 mmol. l(-1). h(-1) for GL; 3.9 +/- 0.3 mmol. l(-1). h(-1) for Nor; P < or = 0.001). We conclude that glycogen recovery from heavy exercise is controlled primarily by the remaining postexercise glycogen concentration, with only a transient synthesis period when glycogen levels are not severely reduced.     

Effects of age and regular exercise on muscle strength and endurance

Twenty male and 20 female non-professional tennis players were classified into two different age groups (n = 10 per group): young active men (30.4 +/- 3.3 years), young active women (27.5 +/- 4.3 years), elderly active men (64.4 +/- 3.7 years), and elderly active women (65.3 +/- 4.5 years). These individuals were matched (n = 10 per group) according to sex, age, height and mass to sedentary individuals of the same socio-economical background: young sedentary men (29.2 +/- 3.4 years), young sedentary women (25.6 +/- 4.4 years), elderly sedentary men (65.2 +/- 3.2 years) and elderly sedentary women (65.6 +/- 4.4 years). An isokinetic dynamometer was used to measure the strength of the knee extensors and flexors (two separate occasions) and the endurance of the extensors. Vastus lateralis electromyogram (EMG) was measured concomitantly. Significant sex, age and exercise effects (P less than 0.001) were observed for peak torque of both muscle groups. The effect of age on extensor strength was more pronounced at high speeds where men were also able to generate larger relative torques than women. No age or sex effects were noted for muscle endurance. However, muscles of active individuals demonstrated a greater resistance to fatigue than those of sedentary individuals. In conclusion, men were found to be stronger than women, age was associated with a decrease in muscle strength, but not of muscle endurance, and tennis players were stronger and had muscles that were more resistant to fatigue than their sedentary pairs in both age groups.(ABSTRACT TRUNCATED AT 250 WORDS)