OBJECTIVESWe determined the relationship between abdominal circumference and the concentration of nitric oxide (NO), an endothelial cell product known to play an important role in the regulation of vascular tone and thrombocyte activations.

METHODSSubjects were 177 men and 339 women aged 40 or over who were free from a history of diabetes or malignancy. Analysis of covariance was applied to examine the gender-specific and smoking-status-specific associations of abdominal fat volume measured as waist circumference, waist-hip ratio, and waist-to-stature ratio, with serum NO level represented by the concentration of NO metabolites (NOx; nitrate plus nitrite).

RESULTSAlthough men showed no statistical association between abdominal fat accumulation and NOx concentration, abdominal adiposity seemed to inversely affect the serum NOx concentration of never- and current-smoking women.

CONCLUSIONOur results suggest that a reduction in NO bioactivity occurs with abdominal fat accumulation in women. The underlying biological mechanism might involve adipocytokines secreted from visceral fat, but is yet to be elucidated.

OBJECTIVESThe aim of this study was to determine whether the serum nitrite plus nitrate (NO( x )) level correlates with biomarkers that are known components of the metabolic syndrome (MetS).

METHODSSerum NO( x ) levels were measured using a commercial kit in 608 Japanese men and women between the ages of 39 and 85 years. Multivariate adjustments for age, smoking status, alcohol consumption and exercise were made in the analysis of covariance (ANCOVA). The components of the metabolic syndrome were defined based on the following criteria: body mass index (BMI) >/=25.0 kg/m(2), glycated hemoglobin (HbA1c) >/=5.6%, systolic blood pressure >/=130 mmHg or diastolic blood pressure >/=85 mmHg, high-density lipoprotein-cholesterol (HDL-C) /=1.69 mmol/l.

RESULTSThe logarithmically transformed age-adjusted serum NO( x ) (lnNO( x )) value was significantly higher in the low HDL-C group (1.76 +/- 0.05 mumol/l; p < 0.05) than MetS component groups (1.65 +/- 0.01 mumol/l) in men, but no difference was found in women. The means of serum lnNO( x ) after multivariate adjustment were 1.64, 1.65, 1.64, 1.66, and 1.81 mumol/l for 0, 1, 2, 3, and 4-5 MetS components for all subjects, respectively. The results of ANCOVA confirmed that the serum lnNO( x ) level was significantly correlated with the clustering of MetS components in both men and women (p < 0.0001 for trend).

CONCLUSIONOur results suggest that an increase in the clustering of MetS components was associated with the increase in serum NO levels in our general population.