Independent association between nocturnal intermittent hypoxemia and metabolic dyslipidemia.

BACKGROUND: There is growing evidence from animal models that intermittent hypoxemia (IH) may induce dyslipidemia. Altered lipid metabolism may contribute to the increased cardiovascular risk observed in obstructive sleep apnea (OSA). In this multisite, cross-sectional study, we tested the hypothesis that there is an independent association between nocturnal IH and dyslipidemia in OSA. METHODS: Fasting serum lipid levels were measured in 2,081 patients (638 women) undergoing nocturnal recording for clinical suspicion of OSA. Multivariate regression analyses were performed to evaluate the independent associations between oxygen desaturation index (ODI) and lipid profile after adjustment for potential confounders, including components of the metabolic syndrome (MS) or the MS itself. Adjusted OR for metabolic dyslipidemia (triglycerides [TG] ≥ 150 mg/dL and high-density lipoprotein cholesterol [HDL-C] ≤ 50 mg/dL for women and ≤ 40 mg/dL for men) according to quartiles of ODI were determined by logistic regression. RESULTS: Total cholesterol and low-density lipoprotein cholesterol were not associated with ODI. In contrast, nocturnal IH and OSA severity were associated with higher TG levels and lower HDL-C levels after adjustment for confounding factors. The association between ODI and TG and HDL-C levels was independent of the MS. Adjusted OR (95% CIs) for metabolic dyslipidemia were 1 (reference), 1.56 (1.24-1.96), 1.72 (1.29-2.29), and 1.93 (1.55-2.41) for ODI ≤ 7, > 7 to ≤ 18, > 18 to ≤ 38, and > 38, respectively (P < .0001 for linear trend). CONCLUSIONS: Nocturnal IH is independently associated with metabolic dyslipidemia, which may predispose patients with OSA to a higher risk of cardiovascular disease.

Increases in waist circumference and weight as predictors of type 2 diabetes in individuals with impaired fasting glucose: influence of baseline BMI: data from the DESIR study.

OBJECTIVE: To evaluate in impaired fasting glucose (IFG) the relative importance of increases in waist circumference and weight on progression to type 2 diabetes. RESEARCH DESIGN AND METHODS: The 9-year incidence of diabetes was studied in 979 men and women with baseline IFG, from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort. RESULTS: Increases in both waist circumference and weight were significantly associated with diabetes incidence. Standardized odds ratios (95% CI) were 1.79 (1.45-2.21) and 1.86 (1.51-2.30), respectively, after controlling for baseline risk factors. The impact of waist circumference increase was greater for BMI <25 kg/m(2) (2.40 [1.63-3.52]) than for BMI >or=25 kg/m(2) (1.66 [1.28-2.16]) and persisted after adjusting for concurrent changes in either insulinemia or the homeostasis model assessment of insulin resistance index. Weight change had a similar impact in both BMI groups. CONCLUSIONS: In individuals with IFG, it is important to monitor and prevent increases in waist circumference, in particular for those with BMI <25 kg/m(2).