Date of Award

January 2020

Document Type

Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Nicola L. Hawley

Abstract

Objectives: (1) To describe accelerometer-measured physical activity among Samoan adults; (2) to determine associations between physical activity and type 2 diabetes and hypertension; and (3) to assess adherence to global physical activity recommendations.

Participants: Three hundred eighty-five Samoan adults aged 30-72 years.

Setting: Participants were recruited from 23 villages on the Samoan island of ‘Upolu (eight urban, seven peri-urban, and eight rural).

Measurements: Self-reported demographic information including age, census region of residence, and occupation was collected. Anthropometric measurements including weight and height were taken in light island clothing, and body mass index was calculated. Sedentary time, light-intensity physical activity, and moderate-to-vigorous intensity physical activity (MVPA) were measured using wrist-worn ActiGraph GT3X+ accelerometers.

Outcomes: Type 2 diabetes was defined as measured hemoglobin A1c ≥ 6.5%, fasting glucose ≥ 126 mg/dL, or self-reported use of diabetes medication. Hypertension was defined as blood pressure ≥ 140/90 mmHg or self-reported use of hypertension medication. Adherence to global physical activity recommendations was defined as ≥ 150 minutes of moderate physical activity or ≥ 75 minutes of vigorous physical activity in a 7-day period.

Results: The sample was 54.5% female, and mean age was 52 years (s.d.10.1). Older age and lower education level were significantly associated with higher mean minutes of sedentary time per day. Younger age and peri-urban (compared to urban) census region of residence were significantly associated with higher mean daily minutes of MVPA. Type 2 diabetes and hypertension were significantly associated with higher daily mean minutes of sedentary time and lower daily mean minutes of MVPA. Sixty or more minutes of MVPA per day was significantly associated with lower odds of type 2 diabetes after adjusting for age, occupation, genotype, and average minutes of weartime. Hypertension and mean daily minutes of MVPA were not significantly associated following adjustment for age and weartime. In a sub-analysis of 234 participants, over 85% of participants met global physical activity recommendations. Adherence to recommendations was significantly associated with younger age and no diabetes or hypertension status.

Conclusions: This study is the first to describe objectively-measured physical activity among a sample of Samoan adults. Findings suggest that current global physical activity recommendations may not be appropriate in this setting where obesity prevalence and caloric intake are high. Longitudinal follow-up is warranted.

Key Words: Samoa, accelerometry, global physical activity recommendations, type 2 diabetes, hypertension, physical activity

Abbreviations: LPA, light-intensity physical activity; MVPA, moderate-to-vigorous intensity physical activity; HbA1c, hemoglobin A1c

Comments

This thesis is restricted to Yale network users only. It will be made publicly available on 05/27/2021

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