Serum lipid profile, sleep-disordered breathing and blood pressure in the elderly: a 10-year follow-up of the PROOF-SYNAPSE cohort

Abstract

ObjectivesDyslipidemia, sleep-disordered breathing (SDB) and hypertension are comorbid factors evidenced in adults, but poorly studied in old people. This study aimed to examine the long-term evolution of the serum lipid profile, and its relationships with SDB and blood pressure (BP) in the elderly. MethodsA ten-year follow-up of the prospective Prognostic Indicator of Cardiovascular and Cerebrovascular Events (PROOF) and the Autonomic Nervous System Activity, Aging and Sleep Apnea/Hypopnea (SYNAPSE) cohort, which initially included 1011 elderly subjects from the general population, and who were untreated by continuous positive airway pressure (CPAP). Serum lipid profile, respiratory polygraphy for SDB and ambulatory blood pressure monitoring were performed. ResultsA total of 266 subjects (male/female 150/116; age 66.2 ± 0.8 years) were reassessed after 9.6 ± 0.7 years (age 75.8 ± 1.2 years). The prevalence of high-risk dyslipidemia decreased from 61.3 to 44.4%, and hypertension from 57.9 to 27.4%. The nocturnal oxygen desaturation index increased (mean + 2.3 ± 6.7 events/hour; p < 0.001), while the mean SaO2 and minimal SaO2 decreased. These variations (Δ) of oxygen desaturation worsened whether or not elderly subjects took anti-hypertensive and lipid-lowering treatments, and were not associated with serum lipid variations. The decrease in diurnal diastolic BP was independently associated with aging, and with the lowering of the waist/hip ratio (ΔW/H) and low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio, while the decrease in diurnal systolic BP only depended on aging and ΔW/H. ConclusionsThe results suggested that the observed worsening of nocturnal oxygen desaturation after 10 years in the elderly was independent of the change in circulating lipids, and not influenced by lipid-lowering treatments. However, the variation in blood pressure remained associated with aging, waist/hip and LDL-C/HDL-C ratios.Trial registry: NCT00759304 and NCT00766584 at clinicaltrials.gov.