Association between Sleep Duration, Bed Time and Obesity in Community-Dwelling Hong Kong Chinese Elderly: A Population-Based Study
Refereed conference paper presented and published in conference proceedings

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AbstractObesity is an important cardiometabolic risk factor among the elderly population because it is associated with many life threatening diseases. Previous studies suggested that sleep duration was associated with obesity, but most of these studies were focusing on younger adults. Numerous studies showed that elderly people generally had poorer sleep patterns than those of the younger adults, as elderly had poorer sleep quality but with earlier bedtime. It remains lack of knowledge if poor sleep patterns increase obesity among elderly population. Thus, this study aimed to examine the association of sleep duration and bed time with body fat percentage (fat%), waist circumference (WC) and BMI among Hong Kong Chinese elderly.
Materials and Methods:
We recruited 208 adults who were aged 65 or above during April - September 2018. We used a standardized questionnaire to collect participant’s information on habitual sleep patterns and other variables. During the recruitment interview, we also measured their anthropometric parameters including height, weight, WC and fat% in their light cloth. Obesity was defined as BMI> 25, WC >88 in women and >102 in men.
We used R program version 3.5.1 to analyze our data. Multiple linear regression, multivariate logistic regression and multinomial logistic regression were used to calculate the association of sleep duration and bed time with fat%, WC and BMI respectively.
On average, participants went to bed at 22:12 and slept for 7.82+1.23 hours. The mean of bedtime shifted from 22:26 in younger elderly (<70 years old) to 21:49 in older elderly (>80 years old). Compared to the category “habitually slept 7-9 hours per day”, elderly who slept <7 hours tended to have higher WC (adjusted odds ratio (AOR)=2.50, 95% confidence interval (95%CI) = 0.91-6.99) after adjusting their age, sex, BMI. Elderly who slept >9 hours have higher fat% (adjusted β = 1.95; p = 0.04), but the association became attenuated with borderline significance (adjusted β = 1.76; p = 0.07) after further adjusting for educational attainment, income per capital, total minutes spent on vigorous and moderate physical activities, and red meat consumption. Compared with those who went to bed at 22:00 – 23:00, elderly who slept earlier was associated with higher WC (AOR=4.59, 95%CI=1.71-13.46), and elderly who slept later was associated with higher fat% (adjusted β = 1.79; p = 0.06) after adjusting the possible confounders. However, there were no significant associations of sleep duration or bed time with BMI.
Our study suggested that poor sleep patterns including sleep <7 hours, >9 hours, and both early and late bedtime were associated with increased fat% and WC among Hong Kong elderlies. If these associations were confirmed prospectively, healthy sleep via means of intervention would be a way to control of the obesity epidemics among elderly.
The authors would like to thank Hiu Man TSOI, Ho Ling KWOK and Ka Yin LAM for their assistance in participants’ recruitment preparation and data collection. Special thanks to Kitty SIN, Karen YIU, CHAI Man Hon, LO Kin Hei, Dan SHUM, Yue Hon WONG for site arrangement.
All Author(s) ListPriscilla Ming Yi Lee, Lap Ah Tse
Name of ConferenceWorld Sleep 2019
Start Date of Conference20/09/2019
End Date of Conference25/09/2019
Place of ConferenceVancouver
Country/Region of ConferenceCanada
LanguagesEnglish-United Kingdom

Last updated on 2020-20-10 at 10:38