Sex differences in the association of physical activity levels and vitamin D with obesity, sarcopenia, and sarcopenic obesity: a cross-sectional study

BACKGROUND

The relationship between vitamin D and sarcopenia was inconsistent between men and women. Physical activity (PA) may interact with vitamin D on sarcopenia. However, the sex-specific relationships of vitamin D, PA and sarcopenia have yet elucidated. We aimed to examine the sex differences in the relation between vitamin D status, PA levels, obesity and sarcopenia in community-dwelling middle-aged and older adults, as well as whether vitamin D status is a modifier in the relationship between PA and sarcopenia.

METHODS

The current study was a cross-sectional study based on the baseline survey of the West China Health and Aging Trend (WCHAT) study. A total of 3713 participants aged ≥ 50y were included in our study. Sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS) 2019 consensus. Obesity was defined by body mass index (BMI) (≥ 28 kg/m2) and body fat mass percentage (≥ 60th percentile in each sex group). 25-hydroxyvitamin D was measured by chemiluminescent microparticle immunoassay and PA was evaluated by a validated China Leisure Time Physical Activity Questionnaire (CLTPAQ). Multinomial logistic regression was performed to examine the relationship between PA, vitamin D and sarcopenia and obesity.

RESULTS

Low PA was significantly associated with higher odds of sarcopenia in women only (OR = 1.70,95%CI:1.18,2.46, p < 0.01). Vitamin D deficiency was only associated with sarcopenia in men (OR = 1.85,95%CI: 1.27,2.69, p < 0.01). Low PA was significantly associated with obesity, sarcopenia, and sarcopenic obesity only in participants with serum 25(OH)D < 20 ng/ml.

CONCLUSIONS

The role of vitamin D and PA in obesity and sarcopenia was different between men and women, and the relationship between PA and sarcopenia was modified by serum vitamin D status. These findings highlighted the need to supplement vitamin D in individuals with physical inactivity and provide different interventions strategies to sarcopenia in men and women.

TRIAL REGISTRATION

Clinical trial number: ChiCTR1800018895.

Cohort Profile: West China Health and Aging Trend (WCHAT)

OBJECTIVES

The West China Health and Aging Trends study (WCHAT) is intended to focus on the research that will guide efforts to reduce disability, maximize health and independent functioning, and enhance quality of life at older ages in different ethnicities. And provide the basis for understanding trends and dynamics in late-life functioning, how these differ in various ethnic subgroups, and the economic or social consequences of aging and disability in western China.

PARTICIPANTS

The cohort enrolled 7536 participants and 7439 participants aged 50 years and older in the baseline in 2018 and every year would be followed up. Finding to date: The data in WCHAT were prospectively collected from Yunnan, Guizhou, Sichuan and Xinjiang by 7 medical institutions. A number of age-related outcome measures were collected though corresponding geriatric assessments. Blood testing, saliva, urine and feces testing are available for all cohort participants. Future plans: The data in WCHAT can be used for various types of epidemiological research, particularly for examining how the culture specific life styles and diet influences geriatrics related outcomes. We are initially planning cohort studies and established a sample biobank in relation to the risk and prognosis of frailty, sarcopenia and other geriatric syndromes. Strengths and limitations of this study: It is a first multi-ethnic cohort study in West China that aimed to investigate the influence of culture specific life styles, diet and living environment on the prevalence of geriatric syndromes like frailty, sarcopenia and so on. This is a prospective multi-center observational study, which will be conducted in various ethnic groups gathering places. This study collected information that related to fatigue, falls, and cognition were obtained through self-reports, which might have recall bias and grouping errors. This study has problems such as the interviewees' refusal to visit, death, going out, and large population mobility may lead to high loss of visit rates. This study collected information from a comparatively healthier elderly population in which external validity was limited.