Prevalence and recognition of obstructive sleep apnea in Chinese patients with type 2 diabetes mellitus

Background: Obstructive sleep apnea (OSA) is associated with disorders of glucose metabolism. Previous studies revealed a high prevalence of OSA among subjects with type 2 diabetes mellitus (DM). The aims of this study were to determine the prevalence of OSA and associated clinical factors in Chinese patients with DM. Methods: All records of the DM clinic at a teaching hospital in Hong Kong were screened between January 2007 and June 2008. Inclusion criteria for patients were Chinese, aged 18 to 75 years, with type 2 DM. Patients with unstable medical illnesses, gestational diabetes, or on renal replacement therapy were excluded. Results: Of 3,489 records screened, 1,859 subjects were eligible. A random sample of 663 (mean age, 58.2 ± 10.8; mean BMI, 26.0 ± 4.6), except six with known OSA, were invited for polysomnography (PSG). Of 165 subjects on which PSG was performed, OSA was diagnosed (apnea-hypopnea index [AHI] ≥ 5.0/h) in 89 subjects (53.9%, median Epworth Sleepiness Scale, 6 [interquartile range 3, 10]). Fifty-four (32.7%) had moderate/severe OSA (AHI ≥ 15/h). The estimated OSA prevalence in this diabetic cohort was 17.5% (24.7% in men, 10.3% in women). Regression analysis identified that AHI was associated independently with higher BMI, advanced age, male sex, and higher diastolic BP (R2 = 29.6%). The adjusted OR of requiring three or more antihypertensive drugs in moderate/severe OSA was 2.48 (95% CI, 1.05-5.87). No association between glycemic control (HbA1c) and sleep was identified. Conclusions: In conclusion, OSA is more prevalent in Chinese adults with DM than in the general population. A high index of suspicion for OSA in patients with DM is warranted, because they may not have overt daytime sleepiness. Trial registry: ClinicalTrials.gov; No.: NCT01172093; URL: www.clinicaltrials.gov. © 2010 American College of Chest Physicians.link_to_OA_fulltex

Periostin, a novel secreted protein involved in the pathogenesis of obesity and type 2 diabetes.

Introduction: Hypertension is a common cardiovascular risk factorwhich contributes to the increased cardiovascular risk in diabetes.Hypoadiponectinaemia has been found in type 2 diabetes, hypertensionand coronary artery disease. A recent study suggests that replenishmentof adiponectin can ameliorate obesity-related hypertension in mice [1].The aim of this study is to assess whether adiponectin also plays a role inhypertension development in humans.Subjects and Methods: A nested case–control study was performed.Normotensive subjects (BP < 130/85 mmHg) were recruited from theHong Kong Cardiovascular Risk Factors Prevalence Study and followed-up prospectively for 5 years. At the year 5 follow-up, 75 recruitedsubjects (cases) had developed hypertension (BP ‡ 130/85 mmHg or onregular anti-hypertensive treatment). Controls consisted of age and sex-matched subjects (n = 150, matched to cases at a ratio of 2:1) whoremained normotensive at 5 years. Blood pressure was measured as themean of two readings taken after sitting for at least 10 min. Adiponectinlevel was measured with an in-house ELISA assay.Results: Hypertensive subjects had more adverse risk factors, includinghigher BMI, waist circumference, waist hip ratio and mean arterialpressure (MAP) at baseline, compared to controls (all P < 0.001). Baseline adiponectin levels were significantly lower in hypertensivesubjects (1.75 ± 0.48 lg/ml vs. 1.93 ± 0.38 lg/ml, hypertensive vs.control, P = 0.003). Logistic regression analysis showed that baselinesex-adjusted adiponectin level (OR 0.32, 95% CI: 0.13–0.82, P = 0.018)was an independent negative predictor of hypertension development at5 years, in a model that included age, BMI, family history of hypertensionand baseline MAP, which were all independent positive predictors ofhypertension.Conclusion: In this Chinese population, hypoadiponectinaemia was anindependent predictor of hypertension development during a 5-yearfollow up.link_to_subscribed_fulltex

Adipocyte–fatty acid binding protein as a biomarker for 35 coronary atherosclerosis

Oral PresentationIntroduction: Obesity is associated with increased cardiovascular risk. Recent studies suggested that adipocyte– fatty acid binding protein (A-FABP) may have a role in mediating obesity-related metabolic and cardiovascular complications. Here, we investigated the association of baseline serum A-FABP with the severity of coronary atherosclerosis at 10 years in a Chinese cohort. Methods: A total of 408 asymptomatic subjects without a history of coronary heart disease (CHD) at baseline underwent computed tomography for coronary artery calcium score assessment (CACS) at 10-year follow-up. Results: Baseline A-FABP was significantly associated with the 10-year CACS (P<0.00001). A-FABP levels correlated with the Framingham risk score (FRS) at baseline (r=0.48, P<0.001). Significant additive effect of A-FABP to FRS in the prediction of coronary atherosclerosis at 10 years was observed, as demonstrated by significant likelihood ratios (P<0.001) and receiver operating characteristics curve analyses. On stepwise multinominal logistic regression analysis, serum A-FABP was a significant independent baseline predictor of CACS at 10 years (OR=2.04, 95% CI=1.22-3.43 for CACS 1-100 vs CACS=0, P=0.007; and OR=2.40, 95% CI=1.19-4.83 for CACS >100 vs CACS=0, P=0.014), together with age and male sex. Conclusion: A-FABP may serve as a useful marker, in combination with current risk assessment tools, to identify individuals at increased risk of CHD. Acknowledgement: This study was supported by the Hong Kong Research Grant Council (HKU7590/06M); Central Allocation (HKU 2/07C), and Hong Kong Innovation and Technology Fund (GHP/027/05)

Hypoadiponectinemia as a predictor for the development of hypertension: A 5-year prospective study

Low circulating levels of adiponectin, an adipokine with insulin-sensitizing, antiatherogenic, and anti-inflammatory properties, are found in hypertensive patients. Adiponectin replenishment ameliorated hypertension in adiponectin-deficient mice or obese, hypertensive mice with hypoadiponectinemia, suggesting an etiologic role of adiponectin in hypertension. We aimed to determine, in this 5-year prospective study, whether hypoadiponectinemia could predict the development of hypertension in a nondiabetic Chinese cohort. A total of 577 subjects (249 men and 328 women) were recruited from the population-based Hong Kong Cardiovascular Risk Factor Prevalence Study and prospectively followed up for 5 years. The relationship of serum adiponectin with the development of hypertension (sitting blood pressure ≥140/90 mm Hg) was investigated in a nested case-control study consisting of 70 subjects who had developed hypertension on follow-up and 140 age- and sex-matched control subjects who were normotensive both at baseline and at year 5. At baseline, serum adiponectin level in the lowest sex-specific tertile was more likely to be associated with hypertension (P=0.003 versus the highest tertile, after adjusting for age, body mass index, fasting insulin, and high-sensitivity C-reactive protein). At year 5, baseline serum adiponectin was a significant independent predictor of incident hypertension in the nested case-control study (P=0.015; age adjusted), together with mean arterial pressure (P<0.001), high-sensitivity C-reactive protein (P=0.018), and body mass index (P=0.004). Normotensive subjects with baseline serum adiponectin levels in the lowest sex-specific tertile had an increased risk of becoming hypertensive (adjusted odds ratio: 2.76; 95% CIs: 1.06 to 7.16; P=0.037 versus highest tertile). Our data suggest that hypoadiponectinaemia may be involved in the pathogenesis of hypertension in humans. © 2007 American Heart Association, Inc.link_to_OA_fulltex