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Objective: To test the association of the C(−55)A polymorphism of the natriuretic peptide clearance receptor (NPRC) with blood pressure (BP), overweight/obesity, and body fat distribution in a large male adult population. Research Methods and Procedures: The study population was from a cross-sectional and follow-up study of 787 untreated male participants in the 1994 to 1995 follow-up examination of the Olivetti Heart Study in Naples (356 of whom were examined previously in 1975). BP and anthropometric measures were taken, and biochemical assays were performed. The NPRC gene polymorphism C(−55)A was evaluated by polymerase chain reaction and HgaI digestion. Results: In the whole study population, there was no difference in BP, BMI, and biochemical tests among genotypes. Considering an A(−55) recessive model of inheritance, the AA subjects had lower BMI and waist circumference and lower prevalence of overweight, obesity, and abdominal adiposity as compared with the CC+CA subjects. On reviewing the characteristics of the subgroup previously examined in 1975, the AA subjects had already lower BMI, and their 20-year rate of overweight and obesity was lower than the CC+CA subjects; no difference was observed in the rate of hypertension. Discussion: Male subjects carrying the A(−55)A NPRC genotype had a significantly lower prevalence of overweight, obesity, and abdominal adiposity. They also had a lower 20-year rate of overweight compared with CC+CA individuals. These findings from a large unselected and untreated male population are in keeping with the recent evidence of a powerful lipolytic and lipomobilizing activity of natriuretic peptides.

Objective: The role of leptin in the association between body mass, central adiposity, and blood pressure (BP) is controversial. This study evaluated the relationship between leptin and BP in relation to body mass index (BMI) and fat distribution in a large sample of untreated male adults. Research Methods and Procedures: The study population was made up of 457 untreated male employees of the Olivetti factory in Naples. Plasma leptin, complete anthropometry, BP, and relevant biochemical variables were measured. Results: Log-transformed plasma leptin levels were directly associated with BMI (r = 0.661, p < 0.001) and waist circumference (r = 0.630; p < 0.001). Leptin also correlated with systolic (r = 0.258) and diastolic (r = 0.277) BP (p < 0.001). The association between leptin and BP was maintained after accounting for age, BMI (or waist circumference), log-insulin, and serum creatinine (p < 0.01); this association was stronger than that with BMI. Logistic regression analysis showed that an increased prevalence of hypertension (BP ≥ 140 and/or 90 mm Hg) was associated with high plasma leptin levels when controlling for age and waist circumference (odds ratio, 1.99; 95%CI, 1.06 to 3.72) or for age and BMI (odds ratio, 1.92; 95%CI, 1.02 to 3.61). Discussion: A graded positive relationship between plasma leptin levels and BP was observed in this sample of untreated male adults. This association was independent of age, BMI, abdominal adiposity, and fasting plasma insulin. Moreover, elevated plasma leptin concentrations were associated with greater probability of hypertension, again independently of potential confounders.