Lower BMI is a predictor of obstructive sleep apnea in elderly Thai hypertensive patients

PURPOSE

The prevalence of both hypertension and obstructive sleep apnea (OSA) are increased in patients with age greater than 60 years. We studied the clinical differences of OSA in hypertensive patients with age greater or less than 60 years. In addition, rate of OSA-induced hypertension in Thai population is limited.

METHODS

We retrospectively reviewed medical records of patients treated at the hypertension/sleep clinic at Srinagarind Hospital, Khon Kaen University, between 2010 and 2011. The inclusion criteria used were hypertensive patients who had at least one symptom of OSA and had been tested for the sleep study. Rate and clinical features of OSA were studied and categorized by age of 69 years. Factors associated with likelihood of having OSA in hypertensive patients age over 60 years were identified by multiple logistic regression analysis.

RESULTS

During the study period, 49 patients met the criteria. Of those, 42 patients (85.71 %) had an apnea-hypopnea index (AHI) of more than 5/h. The average AHI was 22.22 ± 13.86 times/h. The common symptoms of OSA were snoring (100 %), daytime sleepiness (28.57 %), unexplained nocturia (28.57 %), and gastroesophageal reflux disease (28.57 %). The numbers of patients with age less than 60 years and more than 60 years were 20 and 22 cases, respectively. Most patients (88.10 %) had well-controlled blood pressure level. Only BMI was significantly associated with OSA-induced hypertension in patients aged over or equal to 60 years. The adjusted odds ratio was 0.743 (0.560, 0.985).

CONCLUSIONS

OSA is very common in Thai hypertensive patients aged 40-70 years who have at least one symptom of OSA. Lower BMI is a predictor of obstructive sleep apnea in elderly Thai hypertensive patients.

The best criteria to diagnose metabolic syndrome in hypertensive Thai patients

The metabolic syndrome (MS) is commonly found in clinical practice. There are many criteria to diagnose MS. The authors did a cross-sectional study to study the difference among the WHO criteria, the National Cholesterol Educational Program (NCEP) Adult Treatment Panel (ATP III), and the International Diabetes Foundation (IDF) in hypertensive patients. Between July and September 2005, 100 patients (62 women) treated at the hypertension clinic, Srinagarind Hospital were included. The WHO, NCEP A TP III and IDF criteria gave the diagnosis of MS in 37, 33, 60 cases, respectively. The IDF criteria had the significantly highest yield among those three criteria (p < 0.0001). Body mass index (BMI) was the only significant correlated with the diagnosis of MS by the IDF criteria (p-value = 0.04). It also had moderately positive correlated with waist circumference, WC (p < 0.0001, Pearson Correlation 0.58). At the cut point of BMI 23 kg/m2, we suggested the appropriate WC cut-point for Thai hypertensive men and women was 82.5 cm (32.5") and 79.5 cm (31.3"), respectively.