Correlates of Insulin Resistance:
Prevalence of Risk Factors in First-Year Medical Students at
Virginia Commonwealth University
JENNIFER M. HUNT
Advisor: Shelley Harris, Ph.D., M.S.C.
Preceptor: Diane B Wilson, Ed.D., MS, RD
Recent research has demonstrated that certain risk factors: insulin resistance, glucose intolerance, dyslipidemia, hypertension, and obesity tend to cluster in occurrence and strongly predict future disease. All of these components are considered to be independent risk factors for the development of disease. However, when clustered, these risk factors have been shown to have a synergistic effect in increasing the odds for the development of long-term, chronic disease. Little is known about the prevalence of insulin resistance and associated risk factors in a young adult population.
Objectives: To describe gender differences in the prevalence of insulin resistance and associated risk factors in a group of first-year medical students.
Methods: Data collected from the GCRC Wellness Study was used to determine the prevalence of insulin resistance and risk factors in a total of 668 medical students. Risk factors were defined using WHO definitions. Insulin resistance was determined using the homeostasis model assessment (HOMA). Gender differences in the prevalence of insulin resistance were determined using Student’s t-tests for continuous variables and chi-squared tests for categorical variables. Univariate associations with insulin resistance were determined using Pearson’s correlation coefficients. Prevalence odds ratios were calculated to determine the overall association of risk factors in insulin resistant and non-insulin resistant medical students.
Results: The prevalence of insulin resistance and other risk factors ranged from 1% (glucose intolerance) to 45% (low HDL-cholesterol levels). There were not significant gender differences in the prevalence of insulin resistance, however there were differences in the prevalence of other risk factors. Men tended to have increased triglyceride levels and hypertension, while women tended to have lower HDL-cholesterol levels and greater measures of obesity. Insulin resistance was highly correlated with triglycerides, bodyfat measurements and HDL-cholesterol levels in both genders. Prevalence odds ratios suggest that insulin resistant individuals were more likely to have high triglycerides (POR = 3.42), a larger waist circumference (POR = 8.79) and a higher BMI (POR = 5.28) than non-insulin resistant individuals. Notably, insulin resistant men and women are 14.3 times more likely to have two or more risk factors than non-insulin resistant individuals.
Conclusion: Insulin resistance and other risk factors are prevalent in this young adult population. The differences in the distribution of risk factors indicate the influence of gender on risk factor clustering. Future studies should continue to focus on gender differences in the distribution of risk factors for chronic disease. In addition, this study indicates that risk reduction behavioral interventions may be useful for medical students in the future.
