Obesity and type 2 diabetes (T2D) are escalating at alarming rates and disproportionately affect black individuals. High T2D rates observed among blacks cannot be explained by obesity or other established risk factors. Emerging evidence indicates that accumulation of fat in non-adipose tissues (ectopic fat), such as in skeletal muscle and liver, contributes to the development of T2D, independent of obesity. However, it is still unclear if and how these fat depots influence T2D, particularly among high-risk black populations. There remains a need to better understand the role of ectopic fat in T2D especially in black populations. Through the Career Development Award (K01-DK083029) the applicant is currently investigating the epidemiology of skeletal muscle fat infiltration in a well-characterized cohort of black men from the Tobago Health Study. This cohort offers a unique opportunity to study a black population with very little non-African admixture, low levels of total adiposity, low prevalence of potential confounding variables, but with a high prevalence of T2D, especially among non-obese men. Building on this existing study of skeletal muscle fat infiltration, we are proposing a pilot study to add critical measures of abdominal visceral, subcutaneous, muscle, and hepatic fat accumulation by computed tomography (CT) in 300 black men (150 with and 150 without T2D) from the Tobago Health Study, aged 40-80 years. These newly collected data will enable us to test the hypotheses that compared to black men without T2D, black men with T2D have greater fat infiltration 1) in skeletal muscle, and, 2) in liver, independent of visceral, subcutaneous and total body fat. The proposed pilot study will provide important new insight on visceral, muscular, and hepatic fat infiltration and their individual and collective relationship with T2D in a black population at high risk of diabetes. It will also generate essential preliminary data to support a larger scale proposal of ectopic fat infiltration in skeletal muscle and liver. It will also lay the foundation for a future longitudinal study of changes in ectopic fat depots with aging and the relationships of these changes to T2D risk. Finally, the proposed research will be an important step in the applicant's long-term goal to characterize the epidemiology of ectopic fat and to investigate its role in T2D in black populations.

Public Health Relevance

Obesity and type 2 diabetes (T2D) are escalating at alarming rates and disproportionately affect black individuals. High T2D rates observed among blacks cannot be explained by obesity or other established risk factors. Emerging evidence indicates that accumulation of fat in non-adipose tissues (ectopic fat) contributes to the development of T2D, independent of obesity. However, it is still unclear if and how these fat depots influence T2D, particularly among high-risk black populations. Building on the existing study of skeletal muscle fat infiltration in black men at high risk of T2D, we are proposing a pilot study to extend our current measures of adiposity. We will obtain critical measures of abdominal visceral, subcutaneous, muscle, and hepatic fat accumulation by computed tomography (CT), and test for an association with T2D. The proposed pilot study will provide important new insight on visceral, muscular, and hepatic fat infiltration and their individual and collective relationship with T2D in a black population, and will further facilitate the applicant's transition to an independent investigator.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Small Research Grants (R03)
Project #
5R03DK092348-02
Application #
8328607
Study Section
Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK)
Program Officer
Hyde, James F
Project Start
2011-09-05
Project End
2013-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
2
Fiscal Year
2012
Total Cost
$87,561
Indirect Cost
$22,966
Name
University of Pittsburgh
Department
Public Health & Prev Medicine
Type
Schools of Public Health
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Kuipers, A L; Zmuda, J M; Carr, J J et al. (2014) Association of volumetric bone mineral density with abdominal aortic calcification in African ancestry men. Osteoporos Int 25:1063-9