Impact of obstructive sleep apnea on cardiometabolic health in a random sample of older adults in rural South Africa: building the case for the treatment of sleep disorders in underresourced settings

STUDY OBJECTIVES: The association between obstructive sleep apnea (OSA) and increased cardiometabolic risk (CMR) has been well documented in higher-income countries. However, OSA and its association with CMR have not yet been investigated, based on objective measures, in southern Africa. We measured polysomnography-derived sleep characteristics, OSA prevalence, and its association with cardiometabolic diseases in a rural, low-income, African-ancestry sample of older adult participants in South Africa. METHODS: Seventy-five participants completed the study. Body mass index, hypertension, diabetes, dyslipidemia, and HIV status were determined. A continuous CMR score was calculated using waist circumference, random glucose, high-density-lipoprotein cholesterol, triglycerides, and mean arterial blood pressure. Sleep architecture, arousal index, and apnea-hypopnea index for detection of the OSA (apnea-hypopnea index ≥ 15 events/h) were assessed by home-based polysomnography. Associations between CMR score and age, sex, socioeconomic status, apnea-hypopnea index, and total sleep time were investigated by multivariable analysis. RESULTS: In our sample (53 women, age 66.1 ± 10.7 years, 12 HIV+), 60.7% of participants were overweight/obese, 61.3% were hypertensive, and 29.3% had undiagnosed OSA. Being older (P = .02) and having a higher body mass index (P = .02) and higher waist circumference (P < .01) were associated with OSA. Apnea-hypopnea index severity (β = 0.011; P = .01) and being a woman (β = 0.369; P = .01) were independently associated with a higher CMR score in socioeconomic status- and age-adjusted analyses. CONCLUSIONS: In this South African community with older adults with obesity and hypertension, OSA prevalence is alarming and associated with CMR. We show the feasibility of detecting OSA in a rural setting using polysomnography. Our results highlight the necessity for actively promoting health education and systematic screening and treatment of OSA in this population to prevent future cardiovascular morbidity, especially among women

Sleep disorders in low- and middle-income countries: a call for action

Letter to the editor

Assessment of variation in immunosuppressive pathway genes reveals TGFBR2 to be associated with risk of clear cell ovarian cancer.

BACKGROUND: Regulatory T (Treg) cells, a subset of CD4+ T lymphocytes, are mediators of immunosuppression in cancer, and, thus, variants in genes encoding Treg cell immune molecules could be associated with ovarian cancer. METHODS: In a population of 15,596 epithelial ovarian cancer (EOC) cases and 23,236 controls, we measured genetic associations of 1,351 SNPs in Treg cell pathway genes with odds of ovarian cancer and tested pathway and gene-level associations, overall and by histotype, for the 25 genes, using the admixture likelihood (AML) method. The most significant single SNP associations were tested for correlation with expression levels in 44 ovarian cancer patients. RESULTS: The most significant global associations for all genes in the pathway were seen in endometrioid ( p = 0.082) and clear cell ( p = 0.083), with the most significant gene level association seen with TGFBR2 ( p = 0.001) and clear cell EOC. Gene associations with histotypes at p < 0.05 included: IL12 ( p = 0.005 and p = 0.008, serous and high-grade serous, respectively), IL8RA ( p = 0.035, endometrioid and mucinous), LGALS1 ( p = 0.03, mucinous), STAT5B ( p = 0.022, clear cell), TGFBR1 ( p = 0.021 endometrioid) and TGFBR2 ( p = 0.017 and p = 0.025, endometrioid and mucinous, respectively). CONCLUSIONS: Common inherited gene variation in Treg cell pathways shows some evidence of germline genetic contribution to odds of EOC that varies by histologic subtype and may be associated with mRNA expression of immune-complex receptor in EOC patients

Program-Specific Cost-Effectiveness Analysis: Breast Cancer Screening Policies for a Safety-Net Program

AbstractBackgroundEvery Woman Counts (EWC), a California breast cancer screening program, faced challenging budget cutbacks and policy choices.MethodsA microsimulation model evaluated costs, outcomes, and cost-effectiveness of EWC program mammography policy options on coverage for digital mammography (which has a higher cost than film mammography but recent legislation allowed reimbursement at the lower film rate); screening eligibility age; and screening frequency. Model inputs were based on analyses of program claims data linked to California Cancer Registry data, Surveillance, Epidemiology, and End Results data, and the Medi-Cal literature. Outcomes included number of procedures, cancers, cancer deaths, costs, and incremental cost per life-year.ResultsProjected model outcomes matched program data closely. With restrictions on the number of clients screened, strategies starting screening at age 40 years were dominated (not cost-effective). This finding was highly robust in sensitivity analyses. Compared with no screening, biennial film mammography for women aged 50 to 64 years was projected to reduce 15-year breast cancer mortality by nearly 7.8% at $18,999 per additional life-year, annual film mammography was$106,428 per additional life-year, and digital mammography $180,333 per additional life-year. This more effective, more expensive strategy was projected to reduce breast cancer mortality by 8.6$17,050.ConclusionsFor the EWC program, biennial screening mammography starting at age 50 years was the most cost-effective strategy. The impact of digital mammography on life expectancy was small. Program-specific cost-effectiveness analysis can be completed in a policy-relevant time frame to assist policymakers faced with difficult program choices