There has been a dramatic increase in adiposity over the last few decades, resulting in more than 1 billion overweight adults and 300 million obese worldwide. Excess body fat has been associated with several biochemical, lifestyle and other characteristics, as well as with multiple chronic diseases, including type 2 diabetes, coronary disease, stroke, and several site-specific cancers.
However, previous studies have been underpowered to directly compare these associations across various measures of adiposity, including body-mass index, waist-circumference, waist-to-hip ratio, and percentage body fat mass.
The objective of this research is:
(1) to assess precisely any cross-sectional associations of adiposity measures with biological, lifestyle and other characteristics (including biochemistry markers, when available). This analysis will help to (i) determine to what extent adiposity measures share related information; (ii) investigate the determinants of adiposity measures; and (iii) investigate potential biological pathways of the underlying association between adiposity and disease.
(2) to determine within-person variability in adiposity measures using serial measurements.
(3) to characterise and compare the associations of adiposity measures with future risk of all-cause mortality, and, when sufficient events/deaths are available in UK Biobank, with risk of site-specific cancers and cause-specific mortality.
This research involves the use of data only (ie, no samples are required) and will help to better understand factors that affect adiposity levels and clarify the relative importance of adiposity measures on disease risk. The number and the range of risk factors available in UK Biobank provide a unique opportunity to study such associations in all participants with information on weight, height, waist and hip circumference, and percentage body fat. In the first phase, we would also require information on socio-demographic, lifestyle, environment, early life, psychosocial and physical measures. When available in UK Biobank, we would like data on biomarkers and serial measurements of adiposity measures to investigate their within-person variability.