Metabolism: clinical and experimental
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Comparative Study
Associations of middle-aged mother's but not father's body mass index with 18-year-old son's waist circumferences, birth weight, and serum hepatic enzyme levels.
Mitochondrial dysfunction has been reported to contribute to insulin resistance (IR) in the elderly and type 2 diabetes. To test this hypothesis, we examined relations of insulin resistance in young men to their mother's body mass index (BMI) and compared with those to their father's BMI, because as a rule, mitochondrial DNA is exclusively maternally inherited and because mitochondria are fundamental in mediating effects on energy dissipation. We measured heights, weights, waist circumference, systolic and diastolic blood pressure (BP), and biochemical variables in sera from 193 male college students aged 18 to 20 years after an overnight fast. ⋯ After adjustment for sons' BMI, waist circumference and 3 hepatic enzymes were associated with mother's BMI, whereas Lp(a) was associated with both mother's and father's BMI. In multiple regression analysis for HOMA-IR as a dependent variable, BMI of their own (beta=.10, P<.0001) and of their mothers (beta=.04, P=10) and birth weight (beta=-.27, P=.10) emerged as determinants of HOMA-IR of the students(R2=0.30). Our results are consistent with clinical observations of a greater risk of transmission of type 2 diabetes from the mother than the father and suggest that son's IR may be influenced by maternal effect as well as their adiposity.
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Randomized Controlled Trial Clinical Trial
Relationship between S-adenosylmethionine, S-adenosylhomocysteine, asymmetric dimethylarginine, and endothelial function in healthy human subjects during experimental hyper- and hypohomocysteinemia.
Experimental hyperhomocysteinemia after an oral methionine or homocysteine load is associated with impaired nitric oxide-dependent vasodilatation in healthy human beings. However, it remains unproven that this effect is mediated by elevations in plasma homocysteine. There is evidence that an increase in plasma homocysteine may increase the formation of asymmetric dimethylarginine (ADMA), an inhibitor of nitric oxide synthase. ⋯ Plasma S-adenosylmethionine/S-adenosylhomocysteine ratio was significantly (P < .001) increased at 4 hours after methionine (10.9 +/- 0.7) compared with homocysteine (5.4 +/- 0.4), NAC (5.0 +/- 0.3), and placebo (6.0 +/- 0.5). Plasma ADMA concentrations were not altered by any intervention. Our results suggest that endothelial dysfunction due to methionine or homocysteine loading is not associated with an increase in plasma ADMA or a disruption in methylation status.
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Clinical Trial
Serum concentrations of nitric oxide, tumor necrosis factor (TNF)-alpha and TNF soluble receptors in women with overweight and obesity.
The aims of the present study was to examine how overweight and obesity affect serum concentrations nitric oxide (NO) metabolites and to determine whether there is association between serum concentrations tumor necrosis factor (TNF)-alpha and TNF soluble receptors (sTNF-R) in subjects with overweight and obesity. The study groups involved 154 women: 102 obese (81 obese with body mass index [BMI] 30 to 40 kg/m2 and 21 obese with BMI > 40 kg/m2), 24 overweight patients, and 28 lean controls. Serum concentrations of NO metabolites and of TNF-alpha and its soluble receptors (sTNF-R1, sTNFR-2) were measured by enzyme-linked immunosorbent assay (ELISA) kits. ⋯ However, serum concentrations of sTNF-R1 and -R2 did not differ significantly between the overweight group, both obese groups, and controls. In conclusion, we observed increased serum concentrations of TNF-alpha and NO in overweight and obese women. It seems that there is an association between serum concentrations of TNF-alpha and NO; however, this relationship depends on the degree of obesity.
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Uncoupling protein-1 (UCP-1) plays a major role in thermogenesis, and has been implicated in the pathogenesis of obesity and metabolic disorders. The purpose of this study was to estimate the effects of A-3826G polymorphism of the UCP-1 gene on the plasma lipid profiles in 190 Korean obese subjects with a body mass index (BMI) more than 30 kg/m2. Height, weight, BMI, wait-to-hip ratio (WHR), obesity index, and body composition were measured and genotype of UCP-1 was analyzed by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method. ⋯ When the subjects were divided into a normal group and a hyper-LDL cholesterolemia group by LDL cholesterol level of 3.626 mmol/L (140 mg/dL), the frequency of hyper-LDL cholesterolemia was significantly higher in GG type compared with other types by Fisher's exact (chi-square) test (P = .05). When logistic regression analysis was conducted to find the risk factors of hyper-LDL cholesterolemia, the odds ratio was 4.115 (P = .03) for GG type of UCP-1 gene. These results suggest that the GG type of the UCP-1 gene has a strong association with increased LDL cholesterol level and might be a significant risk factor for hyper-LDL cholesterolemia among Korean obese subjects.
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Tumor necrosis factor-alpha (TNF-alpha) seems to be increased in obese subjects, suggesting its role as a proinflammatory cytokine to insulin resistance and metabolic abnormalities in obesity. The aim of this study was to evaluate the relationship between serum TNF-alpha, soluble TNF-alpha receptor 1 (sTNF-R1), TNF-alpha receptor 2 (sTNF-R2), and metabolic syndrome (MS) components and anthropometric indices in obese and non-obese adolescents. A cross-sectional study was performed on obese and non-obese adolescents. ⋯ The serum TNF-alpha was positively correlated with triglyceride (TG) and DBP, and negatively with high-density lipoprotein-cholesterol (HDLC). The sTNF-R1 and sTNF-R2 were correlated with TG and DBP, and TG, respectively. Obese compared with non-obese adolescents exhibited higher concentrations of TNF-alpha and its soluble receptors, and the higher TNF-alpha concentrations were associated with several components of MS in obese adolescents.