Apneia obstrutiva do sono, resistência à insulina e disglicemia em obesos

Abstract

Theoretical substantiation: Obstructive sleep apnea (OSA) is a condition featured by episodes of repeatedly apnea and hipoapnea during sleep, usually progressing, with oxihemoglobin saturation decay, micro awakenings and consequential day somnolence. In adults, obesity is the main causal factor. The association between sleeping apnea and cardiovascular diseases is well established. In recent years evidences that this condition is associated with insulin resistance and diabetes mellitus type 2 (DM 2) has come to light. Objective: Verify if there is a connection between sleeping obstructive apnea, insulin resistance and dysglycemia in obese people. Methodology: Observational transversal section study, considering as exposing variable the sleep apnea and, as closure variable, dysglycemia (any glicose tolerance alteration type) and peripheral insulin resistance. The reference population is constituted of patients from the Nucleus of Obesity's Treatment and Surgery (NOTS). The sample was constituted by patients elected for bariatric surgery between 2007 and 2008. The presence of apnea was investigated through nocturnal polisomnography, and the closure through clinical history, fasting glucose and Homeostasis Model Assessment – Insulin Resistance (HOMA-IR). Results: 365 patients were studied, of whom OSA was diagnosed in 265 (72.6%) and dysglycemia in 128 (35.1%). The HOMA-IR index presented values between 0.6 and 50.2 with a median of 4.7 (2.8 - 6.9). When comparing the patients with no dysglycemia, it was observed that the first group was older and had a higher prevalence of male patients. However, after multivariate analysis, the association that remained statistically significant was among age and male patients. When comparing patients with HOMA-IR> 4.3 and patients with HOMA-IR <4.3, the first group had a higher percentage of male subjects, AHI and BMI, as well as lower levels of minimal O2 saturation. After multivariate analysis, association with age and AHI remains. Conclusions: Dysglycemia in obese patients is associated with age, but not with OSA. Insulin resistance in obese patients is also associated with age, and with IAH. The correlation analysis between the studied variables provided a positive and significant correlation between HOMA-IR and the apnea and hypopnea index (rs = 0.273, p <0.001), and negative and significant between HOMA-IR and minimal O2 saturation (rs = 0.208, p <0.001)