Correlation between the severity of apnea and hypopnea sleep, hypertension and serum lipid and glycemic: a case control study

The purpose of this study was to evaluate the correlation between the severity of obstructive sleep apnea (OSA) and the levels of blood pressure (BP), lipids and glucose, as intermittent hypoxia increases BP, changes the oxidative balance, and can induce the formation of free radicals and atherogenesis. 32 patients were evaluated about BP during wakefulness and sleep, total cholesterol and lipids, LDL (low-density lipoprotein), HDL (high-density lipoprotein), triglycerides, glucose and polysomnography. They were divided into four groups according to the respiratory events per hour of sleep (RDI): control group (RDI < 5), Group I (RDI 5–15), Group II (RDI 15–30), Group III (RDI > 30). There was no increase in BP in groups’ cases, the verification of systolic (p = 0.429) and diastolic (p = 0.475) BP in 24 h, systolic (p = 0.277) and diastolic (p = 0.143) BP during wakefulness, and systolic (p = 0.394) and diastolic (p = 0.703) BP during sleep in the control group. When implementing the Spearman correlation test, a correlation directly proportional to the severity of the disease was not observed. Regarding the level of serum total cholesterol (p = 0.092), LDL (p = 0.242), HDL (p = 0.517), triglycerides (p = 0.947), total lipids (p = 0.602) and glucose (0.355), there was no statistically significant difference between groups (p > 0.05 for all parameters). There is no correlation between the severity of OSA and BP levels in 24 h, during daytime, during the sleep and serum levels of LDL and HDL cholesterol.