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Examines the relationship between habitual fat intake and basal fat oxidation in obese and non-obese Caucasian men and women. Assessment of habitual fat intake by seven-day weighted records; Determination of resting fat oxidation after an overnight fast in weight stable non-diabetic subjects.

OBJECTIVE: Tumor necrosis factor-α (TNF-α) is expressed primarily in adipocytes, and elevated levels of this cytokine have been linked to obesity and insulin resistance. Recently, the A allele of a polymorphism in the 5'-flanking region of the TNF-α gene (G-308A) has been reported to be more frequent in obese than in lean subjects and has also been associated with increased expression of this cytokine in fat tissue and influences fat mass and insulin resistance. We, therefore, examined the relationship between this variant and obesity in a German Caucasian population. SUBJECTS AND METHODS: We genotyped 176 index subjects recruited within the framework of the BErG (Berlin Ernährung Geschwister)- Study for the TNF-α-G-308A polymorphism. Subjects were characterized for weight, height, waist and hip circumference, body mass index (BMI), body composition, glucose tolerance, leptin and angiotensinogen levels. RESULTS: The frequency of the -308A allele (0.18) was similar to that reported previously and genotype distribution was in Hardy-Weinberg equilibrium (GG, n = 118; GA, n = 53; AA, n = 5). There was a significant difference in allele frequencies of the polymorphism by BMI quartiles (I, < 27.3 kg/m²; II, 27.3-31.9 kg/m²; III, 31.9-36.5 kg/m²; IV, > 36.5 kg/m², in each quartile n = 44) with -308A allele carriers having a higher BMI than G allele carriers (P = 0.013). Despite previous smaller studies that have related insulin resistance to the G-308A polymorphism, we found no relationship between glucose and insulin response during an oral glucose tolerance test (OGTT) and the polymorphism. Furthermore, none of the plasma parameters were related to the polymorphism. CONCLUSION: Our findings support the hypothesis that the G-308A polymophism of the TNF-α gene is associated with BMI. The G-308A polymorphism may, therefore, represent a genetic marker for increased susceptibility for obesity in Caucasians. [ABSTRACT FROM AUTHOR]

Individuals whose mean arterial blood pressure is depending on oral salt intake are considered salt-sensitive and are at risk of developing essential hypertension. This study investigates the role of salt-sensitivity with respect to systolic blood pressure reactions under standardized mental stress. Forty-three healthy young males, previously characterized as salt-sensitive (n = 16) or salt-resistant (n = 27) by a dietary regimen, were subjected to multimodal physiological measurement during a computerized stress test and underwent comprehensive psychometrical testing. The most important predictors for systolic blood pressure reactions to stress were the degree of salt-sensitivity, body mass index and psychological characteristics like anxiety. The highest correlations with the degree of saltsensitivity were found for the parameters age, systolic blood pressure reaction under stress, high frequency band of heart rate variability and two psychological variables. The concept of salt-sensitivity is a novel biological component that might contribute to reactivity research in subjects at high risk for essential hypertension. [ABSTRACT FROM AUTHOR]