Sleep Apnea strongly linked to Visceral Adiposity in Geriatric Patients, Study finds
According to researchers from the Peking University First Hospital, Beijing, China, it was found out that visceral adiposity (VA) is strongly associated with obstructive sleep apnea (OSA) in elderly patients, while general adiposity linkage to obstructive sleep apnea (OSA) in non-elderly patients is known.
The study is published in the Neurology Live.
"Although some subjects may have never been clinically categorized as overweight or obese, if they have increased VA, they may be at increased risk of OSA and its adverse health outcomes. However, this hypothesis needs yet to be tested in the elderly," described Xinmin Liu, MD, president and respiratory specialist and the lead author of the study.
The researchers evaluated a total of 169 patients aged at least 65 years (elderly) and 142 patients aged less than 65 years (non-elderly) referred for overnight polysomnography (PSG). More than 80% of participants were men (82.3% in elderly and 84.5% in non-elderly).
Mild or no OSA was present in 69 participants (41% of total; 38 in elderly and 31 in non-elderly), moderate OSA was present in 104 (62% of total; 47 in elderly and 57 in non-elderly) and severe OSA was present in 138 (82% of total; 84 in elderly and 534 in non-elderly).
Patients reported smoking (25.1%) and drinking (23.2%), as well as comorbidities such as dyslipidemia (n = 263), hypertension (n = 229), thyroid diseases (n = 171), fatty liver (n =139), coronary heart disease (n = 122), diabetes (n = 105), gastroesophageal reflux disease (n = 69), hyperuricemia (n = 78), stroke (n = 66), chronic obstructive pulmonary disease (n = 25), cancer (n = 24), and chronic kidney disease (n = 20).
The results showed the following findings-
a. Increasing OSA severity was associated with increasing markers of obesity such as BMI, waist circumference (WC), hip circumference (HC), WC/HC ratio, NC/height (H) ratio, WC/H ratio, conicity index, SA, and VA (all P <.02) but was not associated with neck circumference (NC) and VA/subcutaneous adiposity (SA) ratio.
b. There was a significant interaction between OSA severity and age only for VA/SA (P <.005), which increased with OSA severity in the non-elderly and decreased in the elderly, although both VA and SA increased with OSA severity.
c. Compared with the non-elderly, the elderly showed higher conicity index.
d. VA/SA, lower BMI, NC, WC, HC and SA. WC/HC, NC/H, WC/H and VA increased with OSA severity across both groups (all P <.05).
e. BMI, WC, HC, WC/HC, WC/H, conicity index, VA and SA were significantly associated with apnea-hypopnea index (AHI) in the elderly, while BMI, NC, WC, HC, WC/HC, NC/H, WC/H, VA, SA and VA/SA were significantly associated with AHI in the non-elderly.
f. The strongest correlations were WC/H with AHI in the elderly (β = 0.296; P <.05) 0.5 and VA (β = 0.422; P <.01), BMI (β = 0.395; P <.01), and WC/H (β = 0.376; P <.01) in the non-elderly.
g. After adjusting for age, sex, cigarette smoking, alcohol drinking and main comorbidities, BMI, VA and VA/SA, explained 25.9% of AHI variability in the non-elderly and 17.2% variability in the elderly.
Hence, it was concluded that "the differences in OSA associations may suggest the need for age-specific screening and therapeutic strategies. However, the results should be considered preliminary and point to the need for future prospective longitudinal studies in a large cohort to elucidate this issue and to explore possible etiological differences between the elderly and the non-elderly."