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Background. The restrictive, but not the obstructive respiratory dysfunction, is associated with an increased risk of developing type 2 diabetes mellitus. Our aim was to verify in an elderly nondiabetic population whether a restrictive respiratory pattern was associated with a higher prevalence of metabolic syndrome and increased insulin resistance than were obstructive and normal respiratory patterns. Methods. We performed a cross-sectional study of 159 consecutive nondiabetic elderly persons attending two social centers. According to their spirometric pattern, volunteers were classified into the following categories: normal spirometry, obstructive (forced expiratory volume in 1 second/forced vital capacity < 0.70), and restrictive pattern (forced vital capacity < 80% predicted, forced expiratory volume in 1 second/forced vital capacity [greater than or equal to] 0.70). Independent correlates of the metabolic syndrome were identified. Results. The prevalence of metabolic syndrome was higher in restrictive (56%) than in both normal (21.4%, p = .001) and obstructive volunteers (12.9%, p = .001). Insulin resistance, as assessed by the log transformation of the HOmeostasis Model Assessment (HOMA), was higher in restrictive than in obstructive and normal volunteers (1 [+ or -] 0.6 vs 0.3 [+ or -] 0.6 and 0.5 [+ or -] 0.5, p < .001). Restriction was an independent correlate of metabolic syndrome, also after adjustment for waist circumference and body mass index (odds ratio = 3.23, 95% confidence interval, 1.23-8.48: p = .01). Conclusion. Restrictive, but not obstructive respiratory pattern, is associated with metabolic syndrome and insulin resistance, and does not only reflect a limitation of ventilation due to visceral obesity. Metabolic abnormalities likely mediate cardiovascular risk in patients with restrictive respiratory impairment.

Abstract Background Endothelium-derived nitric oxide (NO) mediates the arterial dilation following a flow increase (i.e. flow-mediated dilation, FMD), easily assessed in the brachial artery. NO is also involved in cerebral hemodynamics and it is supposed to trigger vascular changes occurring during migraine. This study aimed at investigating whether migraine patients present an altered response to NO also in the peripheral artery system. Methods We enrolled 21 migraineurs (10 with aura [MwA], 11 without aura [MwoA]), and 13 controls. FMD was evaluated with ultrasound in all subjects by measuring the percentage increase of the brachial artery diameter induced by hyperaemia reactive to sustained cuff inflation around the arm above systolic pressure. FMD values were then normalized for shear stress. Results Normalized FMD values were higher in patients with MwA (28.5 10-2%.s) than in controls (9.0 10-2%.s) and patients with MwoA (13.7 10-2%.s) (p < 0.001). FMD was over the median value (19%) in 23.1% of controls, in 45.5% of the MwoA patients, and in 90% of the MwA patients. Conclusions Migraineurs with aura present an excessive arterial response to hyperaemia, likely as an effect of an increased sensitivity to endothelium-derived nitric oxide. This phenomenon observed peripherally might reflect similar characteristics in the cerebral circulation.