Continuous positive airway pressure therapy improves arterial elasticity in patients with obstructive sleep apnea.

BACKGROUND: Reduced arterial elasticity is an important mediator of accelerated atherogenesis and consequent increased cardiovascular morbidity in obstructive sleep apnea (OSA). The aim of our study was to investigate whether continuous positive airway pressure (CPAP) therapy may improve arterial elasticity in subjects with OSA. METHODS: In 44 subjects with OSA, we measured arterial elasticity by applanation tonometry before and after 6 months of treatment with CPAP. Nine OSA+ subjects withdrew from the study. RESULTS: The 35 patients with OSA who completed the 6-month CPAP treatment showed a marked reduction in both the large artery (LAEI, P=0.001) and small artery (SAEI, P=0.009) elasticity indices, independent of potential confounders. In OSA+ subjects who withdrew from the study, SAEI and LAEI did not change significantly over time. CONCLUSIONS: Six months of CPAP therapy improves arterial elasticity in subjects with OSA.

Arterial elasticity and plasma levels of adiponectin and leptin in type 2 diabetic patients treated with thiazolidinediones.

BACKGROUND: Thiazolidinediones (TZDs) improve peripheral insulin sensitivity, but the effect on arterial stiffness is less clear. The aim of the present study was to assess the differential effect of pioglitazone or rosiglitazone on arterial stiffness and plasma levels of adiponectin and leptin in patients with type 2 diabetes mellitus. METHODS: Thirty-five type 2 diabetic subjects were randomly assigned to receive pioglitazone (30 mg/day; n = 14), rosiglitazone (4 mg/day; n = 11), or placebo (medical nutrition therapy; n = 10) for 12 weeks. Changes in plasma glucose, glycosylated hemoglobin, insulin resistance (HOMA-IR), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, adiponectin, and leptin were evaluated at baseline and after 12 weeks. In parallel, large arterial compliance (C1) and small arterial compliance (C2) were measured at baseline and at the end of treatment period. RESULTS: At 12 weeks, the rosiglitazone (P = 0.026) and pioglitazone (P = 0.004) groups had a significant increase from baseline in adiponectin that was not seen in the medical nutrition therapy group. No significant changes in plasma leptin and in C1 and C2 elasticity indexes were observed over the entire study period in any of the treatment groups. CONCLUSIONS: In this study of patients with type 2 diabetes, treatment with TZDs was associated with a significant improvement in adiponectin levels, although no significant effects were seen on leptin levels and arterial elasticity.