Prevalence of metabolic syndrome diagnosis in patients with obstructive sleep apnoea syndrome according to adopted definition

Abstract

Introduction: Metabolic syndrome (MS), which is connected with enlarged cardiovascular risk, is common in patients with OSAS. The aim of the study was to estimate the prevalence of MS in patients with OSAS according to two definitions of MS (criteria from NCEP-ATP III from 2001 versus criteria from IDF 2005).

Material and methods: Materials consisted of 155 males and 18 females with OSAS (mean AHI 44 ± 22 h-1), obesity (BMI 31.8 ± 5.0 kg/m2), aged 53.9 ± 9.3 years (mean ± SD). Serum lipids, glucose, body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) were measured in all patients.

Results: According to first definition (NCEP - ATP III from 2001), MS was diagnosed in 98 patients (56% of the whole group - MS1 group) compared to 120 patients (69% of the whole group - MS2 group) diagnosed according to the second definition (IDF from 2005), p < 0.05. No differences in BMI and WC between the groups were found. Significant differences in WHR were noted (MS1 group: 1.005 ± 0.05 vs. MS2 group: 1.027 ± 0.06, p < 0.05). Patients from the MS2 group had higher cholesterol HDL compared to the MS1 group (52.3 ± 12.1 mg/dl vs. 42.3 ± 12.1 mg/dl, p < 0.05). Serum triglyceride concentrations were significantly higher in the MS1 group than in the MS2 group (228 ± 122 mg/dl vs. 122 ± 49 mg/dl, p < 0.05). There were no differences in OSAS severity between the MS1 and MS2 group. In both groups weak correlations between diagnosis of MS and AHI were found (r = 0.19 for MS1 and r = 0.21 for MS2, p < 0.05) They are, however, clinically insignificant.

Conclusions: The IDF definition from 2005 of metabolic syndrome indeed increases the frequency of diagnosis of metabolic syndrome in patients with OSAS. We did not observe essential clinical correlation among the degree of OSAS severity and recognition of metabolic syndrome in the MS1 or in the MS2 group.