We studied the influence of glucose metabolism on the nycthemeral blood pressure (BP) pattern and arterial distensibility in 33 nontreated hypertensive patients, 45.6 +/- 8.5 years old, with elevated waist/hip ratio. All patients underwent an ambulatory BP monitoring, a pulse wave velocity (PWV) measurement, and an oral glucose tolerance test. The ratio of mean nocturnal:diurnal systolic BP (N/D ratio) was used to assess nycthemeral BP variability. N/D ratio correlated positively with PWV (r = 0.62; P < .01). When considered according to their glycemic status, N/D ratio and PWV were significantly higher (P < .05; P < .01) in diabetics and in glucose intolerants compared to patients with normal glucose levels. Our data indicate that the nycthemeral BP pattern was different according to the metabolic status. The loss of nocturnal decline in BP is associated with carbohydrate disturbances and reduced arterial stiffness.