Erkin M. Mirrakhimov

Prevalence of obstructive sleep apnea in Asian adults: a systematic review of the literature

BackgroundObstructive sleep apnea (OSA) is a common disease, affecting approximately 2% of women and 4% of men residing in Western communities. No systematically reviewed data are available about the prevalence of this disease in Asia, the most heavily populated continent.MethodsPubMed/Medline, Scopus and Google Scholar were searched for articles published from 1993 to May 2012 that reported the prevalence of OSA diagnosed via sleep monitoring and the prevalence of patients at risk for OSA as assessed by symptomatology and/or sleep questionnaires. We have also searched abstract database of major pulmonary and sleep scientific societies for relevant abstracts presented from 2010 to 2012. The following inclusion criteria were used: articles published in English, age ≥ 18 years, ≥ 100 participants in studies using sleep monitoring for the diagnosis of OSA, ≥ 300 participants in studies using questionnaires to detect patients at high risk for OSA. Exclusion criteria: duplicate publications, studies reporting the prevalence of central sleep apnea only, hospital based studies as well as studies assessing OSA prevalence among patients with resistant arterial hypertension, chronic kidney disease, heart failure and in patients with concomitant neurological disease.ResultsTwenty four articles were found to meet the inclusion criteria, covering 47,957 subjects (26,042 men and 21,915 women) and four relevant abstracts were noted. OSA prevalence ranged from 3.7% to 97.3%. Male gender, older age, a higher BMI and waist to hip ratio, greater neck circumference, arterial hypertension, smoking, snoring and daytime sleepiness were associated with OSA. Sample size, difference between the populations studied and the fact that some works included patients with a high pre-test probability of OSA explain the difference in prevalence rates.ConclusionThis systematic review highlights the lack of data regarding the prevalence of OSA in Asians. Only a few studies provide an approximate estimate of the OSA burden in some Asian communities.

An association between TRP64ARG polymorphism of the B3 adrenoreceptor gene and some metabolic disturbances.

BackgroundsB3 adrenoreceptors (ADRB3) are abundant in adipose tissue and play the role in its metabolism and lipolysis. Some variants of the ADRB3 gene may predispose subjects for the development obesity and metabolic abnormalities in the setting of modern sedentary lifestyle. ADRB3 gene polymorphism association with metabolic disturbances has never been studied before in the ethnic Kyrgyz population.AimTo study an association between Trp64Arg polymorphism of the ADRB3 and metabolic syndrome (MS) components in an ethnic Kyrgyz group.Materials and methods213 Ethnic Kyrgyz volunteers over the age of 30 were enrolled in the study. The assessment plan for each individual comprised of general physical and anthropometric exams as well as laboratory tests (glucose, lipid panel, insulin) and genotyping by Trp64Arg polymorphism of the ADRB3. MS diagnosis was consistent with modified ATP III criteria (2005). Logistic regression analysis was performed to test the potential independent association between Arg64 allele with obesity, abdominal obesity (AO) and arterial hypertension (AH).ResultsTrp64Arg polymorphism of the ADRB3 was assessed in 213 individuals (145 men, 68 women) aged 30-73 (mean age 50.7 ± 7.6). Arg64 allele frequency was 0.239; ADRB3 genotype distribution among participants was: Trp64 homozygotes 54.5%, Trp64Arg 43.2% and Arg64 homozygotes 2.3%. There was an association between Trp64Arg и Arg64Arg genotypes and higher BMI, WC and obesity frequency (p < 0.00009), AO (p < 0.01), type 2 diabetes mellitus (DM) (p < 0.005) and lower high density cholesterol (HDL-C) level (p < 0.03). The logistic regression analysis showed the correlation of the Arg64 allele with obesity (OR 3.159; 95% CI 1.789-5.577) and AO (OR 1.973; 95% CI 1.118-3.481). The association between Arg64 allele and AH lost its significance after adjustment for obesity.ConclusionArg64 allele of the ADRB3 gene in the studied group has an association with MS components such as obesity, AO and decreased HDL-C level.

Pooling and expanding registries of familial hypercholesterolaemia to assess gaps in care and improve disease management and outcomes: Rationale and design of the global EAS Familial Hypercholesterolaemia Studies Collaboration

BACKGROUND The potential for global collaborations to better inform public health policy regarding major non-communicable diseases has been successfully demonstrated by several large-scale international consortia. However, the true public health impact of familial hypercholesterolaemia (FH), a common genetic disorder associated with premature cardiovascular disease, is yet to be reliably ascertained using similar approaches. The European Atherosclerosis Society FH Studies Collaboration (EAS FHSC) is a new initiative of international stakeholders which will help establish a global FH registry to generate large-scale, robust data on the burden of FH worldwide. METHODS The EAS FHSC will maximise the potential exploitation of currently available and future FH data (retrospective and prospective) by bringing together regional/national/international data sources with access to individuals with a clinical and/or genetic diagnosis of heterozygous or homozygous FH. A novel bespoke electronic platform and FH Data Warehouse will be developed to allow secure data sharing, validation, cleaning, pooling, harmonisation and analysis irrespective of the source or format. Standard statistical procedures will allow us to investigate cross-sectional associations, patterns of real-world practice, trends over time, and analyse risk and outcomes (e.g. cardiovascular outcomes, all-cause death), accounting for potential confounders and subgroup effects. CONCLUSIONS The EAS FHSC represents an excellent opportunity to integrate individual efforts across the world to tackle the global burden of FH. The information garnered from the registry will help reduce gaps in knowledge, inform best practices, assist in clinical trials design, support clinical guidelines and policies development, and ultimately improve the care of FH patients.

Cut off values for abdominal obesity as a criterion of metabolic syndrome in an ethnic Kyrgyz population (Central Asian region).

BackgroundPeople of different racial and ethnic backgrounds have a distinct pattern of central fat deposition, thus making it necessary to devise a race based approach for the diagnosis and evaluation of abdominal obesity (AO). This is the first study to determine the optimal waist circumference (WC) cutoff values for definition of AO in an ethnic Kyrgyz population.Methods323 persons of Kyrgyz ethnicity (183 women and 140 men), with a mean age of 51.8 ± 9.5 years old were included in the study. Measurement of blood pressure (BP), anthropometric data (including body mass index calculation and WC measurement), fasting blood sugar, serum lipid parameters and insulin were performed in all examined individuals. Insulin resistance (IR) was considered as HOMA index (insulin × fasting glucose/22.5) ≥ 2.77. Sensitivity and specificity for the presence of IR or two other criteria of MS (according to the international classification, 2009) were calculated by using receiver operating characteristic (ROC) curves for men and women separately.ResultsThe optimal sensitivity and specificity obtained from the ROC curves for IR were 88 cm in women (sensitivity of 0.85, 95%CI (0.72-0.93), specificity of 0.58, 95%CI (0.49-0.66)) and 94 cm for men (sensitivity of 0.8, 95% CI (0.65-0.91), specificity of 0.61, 95% CI (0.51-0.71)). The data from the ROC curve for any two other MS criteria confirmed the results and the WC 88 cm in women (sensitivity of 0.82, 95% CI (0.72-0.9), specificity of 0.72, 95% CI (0.62-0.8)) and 94 cm in men (sensitivity of 0.74, 95% CI (0.62-0.84), specificity of 0.73, 95% CI (0.61-0.83)) were corresponded to the optimal sensitivity and specificity.ConclusionWC ≥ 88 cm and ≥ 94 cm should be used as a criterion for the diagnosis of AO for Kyrgyz women and men respectively based on these results.

Association between sleep apnoea and pulmonary hypertension in Kyrgyz highlanders

This case–control study evaluates a possible association between high altitude pulmonary hypertension (HAPH) and sleep apnoea in people living at high altitude. Ninety highlanders living at altitudes >2500 m without excessive erythrocytosis and with normal spirometry were studied at 3250 m (Aksay, Kyrgyzstan); 34 healthy lowlanders living below 800 m were studied at 760 m (Bishkek, Kyrgyzstan). Echocardiography, polysomnography and other outcomes were assessed. Thirty-six highlanders with elevated mean pulmonary artery pressure (mPAP) >30 mmHg (31–42 mmHg by echocardiography) were designated as HAPH+. Their data were compared to that of 54 healthy highlanders (HH, mPAP 13–28 mmHg) and 34 healthy lowlanders (LL, mPAP 8–24 mmHg). The HAPH+ group (median age 52 years (interquartile range 47–59) had a higher apnoea–hypopnoea index (AHI) of 33.8 events·h−1 (26.9–54.6) and spent a greater percentage of the night-time with an oxygen saturation <90% (T<90; 78% (61–89)) than the HH group (median age 39 years (32–48), AHI 9.0 events·h−1 (3.6–16), T<90 33% (10–69)) and the LL group (median age 40 years (30–47), AHI 4.3 events·h−1 (1.4–12.6), T<90 0% (0–0)); p<0.007 for AHI and T<90, respectively, in HAPH+ versus others. In highlanders, multivariable regression analysis confirmed an independent association between mPAP and both AHI and T<90, when controlled for age, gender and body mass index. Pulmonary hypertension in highlanders is associated with sleep apnoea and hypoxaemia even when adjusted for age, gender and body mass index, suggesting pathophysiologic interactions between pulmonary haemodynamics and sleep apnoea. PH in highland residents is associated with sleep apnoea, suggesting a pathophysiologic interaction http://ow.ly/CQ1k305CQeq

Influence of one-year treatment with lovastatin on myocardial remodeling and ischemia in patients with coronary artery disease.

OBJECTIVE Emerging evidence assumes that statins have a benefit to influence the myocardial remodeling and ischemia in patients with coronary artery disease (CAD). Our aim was to investigate the possible and direct favorable effects of lovastatin on left ventricular (LV) systolic, diastolic function and myocardial ischemia in patients with CAD. METHODS This randomized prospective study consisted of 83 patients (46 males; mean age 54.3 ± 6.5 years) with CAD and dyslipidemia. All patients were randomized to following groups: the 1st group (n=44) received lovastatin (20-60 mg/day), hypolipidemic diet and physical training; the 2nd group (n=39) - hypolipidemic diet and physical training. Lipid spectrum, Doppler-echocardiography, bicycle exercise test and 24-hour ambulatory electrocardiographic monitoring were done at baseline and were repeated after 12 months of treatment. The data were analyzed by using the paired and unpaired Students t-tests. RESULTS In the 1st group there was an improvement of lipid spectrum (p=0.05) without significant changes of liver transaminases and other side effects. After treatment LV ejection fraction increased from 59.8 ± 8.04 to 62.9 ± 4.43% in lovastatin alone group (p=0.01). Unlike 2nd group, the 1st groups patients had also reduction of myocardial ischemia: increased exercise time (5.21 ± 1.81 vs. 5.96 ± 1.76 min; p=0.05), METS (4.42 ± 0.6 vs. 4.78 ± 0.7; p=0.05), magnitude (1.12 ± 0.34 vs. 0.81 ± 0.19 mm; p=0.05) and duration (2.16 ± 0.67 vs. 1.04 ± 0.46 min, p=0.01) of ST segment depression , as well as number of leads with ST segment depression (2.18 ± 0.72 vs. 1.31 ± 0.67; p=0.05). CONCLUSION Lipid-lowering therapy with lovastatin improved the LV systolic function and decreased myocardial ischemia.

Lipids and leptin level in natives of Kyrgyzstan.

OBJECTIVES A possible link between obesity and impaired lipid metabolism is leptin, the 167-amino acid protein, secreted by adipocytes. The content of leptin in the body is closely associated with body mass index (BMI). Data obtained from studies on the association of leptin with dyslipidemia are contradictory. The level of leptin has not been studied in the ethnic Kyrgyz population previously. The purpose of this study was to investigate the relationship between leptin and lipid parameters in a group of ethnic Kyrgyz. STUDY DESIGN The study included 322 ethnic Kyrgyz (145 males, 177 females) aged ≥30 years, living in Kyrgyzstan. Measurement of anthropometric parameters (height, weight, waist circumference [WC], hip circumference [HC]) and blood pressure (BP) was done. Laboratory tests included blood glucose (fasting) in plasma, lipid profile (total cholesterol [TC], triglycerides [TG], high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol), and serum leptin. RESULTS Leptin was positively correlated with BMI, WC and TG in both sexes and with TC in males. CONCLUSION Leptin is associated with BMI, WC and TG in both sexes of Kyrgyz and with TC in Kyrgyz males.

Rhabdomyolysis: Some Extra Clues to Diagnosis

journal.publications.chestnet.org Affi liations: From the VA Greater Los Angeles Healthcare System and David Geffen School of Medicine at the University of California, Los Angeles. Funding/Support: Funding and support for the REVEAL Registry were provided by Cotherix Inc and its affi liate Actelion Pharmaceuticals US Inc. Financial/nonfi nancial disclosures: The authors have reported to CHEST the following confl icts of interest: Dr Bersohn has received grant/research support from Actelion Pharmaceuticals US Inc; Bayer AG; Biotronik SE & CoKG; Medtronic, Inc; Sorin Group; and St. Jude Medical, Inc. Dr Shapiro has received research grants from Actelion Pharmaceuticals US Inc; Bayer AG; GeNO LLC; Gilead Sciences Inc; Ikaria, Inc; Medtronic, Inc; and United Therapeutics Corp and has served as a consultant for United Therapeutics Corp and as a speaker for Actelion Pharmaceuticals US Inc, United Therapeutics Corp, and Gilead Sciences Inc. Correspondence to: Malcolm M. Bersohn, MD, PhD, VA Greater Los Angeles Healthcare System, Cardiology (111E), 11301 Wilshire Blvd, Los Angeles, CA 90073; e-mail: mbersohn@ucla.edu

High-sensitivity cardiac troponin in patients with stable chronic obstructive pulmonary disease: looking beyond the lungs

To the Editor We read with interest the recently published article by Neukamm et al 1. The authors enrolled studied the levels of high-sensitivity cardiac troponin (hs-cTnT) in 101 patients with a stable chronic obstructive pulmonary disease (COPD), and compared them to a randomly chosen sample of 120 individuals from a general population. Patients with COPD were older, had a greater …

Obstructive sleep apnea and dyslipidemia: importance of the liver axis

To the Editor: We read the recently published article by Adedayo et al. with particular interest [1]. The authors summarized the scientific data on obstructive sleep apnea (OSA) and dyslipidemia. We are grateful to the authors for their motivation to write this article and, thus, maintain clinical interest to this exceptionally important medical disorder. Nevertheless, we believe that certain aspects should be emphasized. It is a well-known fact that most lipid particles including triglycerides, cholesterol, and their carrier proteins are produced predominantly in the liver [2]. Thus, it is theoretically plausible that the liver is a potential target for intervention. Indeed, scientific evidence highlights this possibility. OSA leads to a state of chronic intermittent hypoxia, with subsequent alterations in fundamental biochemical processes including an increase in expression of hypoxia-inducible factor family and an enhancement in sympathetic output [3]. This is well known that upregulation of sympathetic activity lead to activation of hormone sensitive lipase with resultant lipolysis and increase in circulating free fatty acids (FFA) [4]. Afterwards, FFAs are taken by the liver and used in the production of triglyceride rich lipoproteins and may even mediate insulin resistance and liver steatosis [5]. Moreover, this mechanism was found to be associated with an accelerated progression of concomitant cardiovascular disease in patients with heart failure with low ejection fraction [6]. Furthermore, hyperinsulinemia may upregulate de novo liver lipid synthesis via activation of sterol regulatory element binding protein-1 [7, 8] and subsequent upregulation of stearoyl coenzyme A desaturase 1 and diacylglcyeroltransferase [9, 10]. Indeed, OSA may be independently associated with insulin resistance, overt type 2 diabetes mellitus, and dyslipidemia, which may be mediated by underlying nonalcoholic fatty liver disease [11]. A potential sketch of OSArelated dyslipidemia is presented in Fig. 1. Finally, we want to express our sincere gratitude to the authors for their work, which will further stimulate the research in this area.