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Obesity and Diabetes Risks in Diverse Cohort

Apr 25, 2025

The Obesity Epidemic and Rising Diabetes Incidence in a Low-Income Racially Diverse Southern US Cohort

Abstract

Background

  • Obesity is a major risk factor for diabetes.
  • The study explores the magnitude of risk and variation between blacks and whites in a southern US population heavily affected by obesity.

Methods

  • Study involved 24,000 black and 14,064 white adults aged 40-79 from the Southern Community Cohort Study.
  • Participants were followed for up to 10 years (median 4.5 years).
  • Incidence rates, odds ratios (OR), and 95% confidence intervals (CI) were calculated based on BMI and other factors such as tobacco/alcohol use, diet, physical activity, and socioeconomic status (SES).

Results

  • Diabetes risk increased with rising BMI, with trends differing between races (p-interaction < .0001).
  • For BMI ≥ 40 kg/m², the adjusted OR for diabetes was 11.9 for whites and 4.0 for blacks.
  • Diabetes incidence was more than double in blacks compared to whites at normal BMI, but this racial difference attenuated at higher BMIs.

Conclusions

  • High rates of obesity-associated diabetes observed.
  • Effective strategies are needed to curb obesity to prevent a rise in diabetes cases.

Introduction

Obesity Trends

  • National surveys show obesity has risen since the 1980s, especially in the South.
  • Higher obesity prevalence among blacks and low-income groups.
  • Obesity is a known risk factor for Type 2 diabetes.

Study Context

  • Conducted within a diverse cohort in the southern US overlapping with the obesity belt.
  • SCCS participants largely from underserved populations.

Methods

Study Design and Participants

  • Southern Community Cohort Study targets health disparities among blacks and whites.
  • Includes over 85,000 adults, two-thirds African American, aged 40-79.
  • Data collected through questionnaires on demographics, lifestyle, and medical history.
  • Follows participants for health status updates and diabetes incidence.

Statistical Analysis

  • Logistic regression models used to estimate ORs for incident diabetes.
  • Models assessed BMI, smoking, alcohol, diet, physical activity, SES, etc.

Results

Diabetes Incidence

  • 17% of blacks and 9% of whites reported newly diagnosed diabetes.
  • Diabetes incidence higher among those with lower education and income.

BMI and Diabetes

  • High BMI was a strong risk factor for diabetes in both blacks and whites.
  • Racial differences in ORs for diabetes with BMI noted, stronger trends among whites.

Other Risk Factors

  • Smoking linked to higher diabetes risk.
  • Alcohol consumption showed reduced diabetes risk.
  • Physical activity and healthier eating modestly associated with lower diabetes incidence.

Discussion

Key Findings

  • Obesity epidemic linked to rising diabetes incidence.
  • Higher diabetes risk found in low SES and obese groups.
  • Stronger BMI-diabetes link in whites than blacks.

Implications

  • Urgent need for obesity prevention strategies.
  • Addressing SES disparities may benefit diabetes prevention efforts.

Acknowledgments

  • Study supported by Vanderbilt University Medical Center and National Cancer Institute.

Data Availability

  • Data available through SCCS, subject to review for privacy concerns.

Funding

  • Supported by NIH grants and other funding bodies.