The association of metformin use with prostate cancer aggressiveness among Black Americans and White Americans in a population-based study

PURPOSE

Metformin has been associated with a reduced incidence of prostate cancer and improved prostate cancer outcomes. However, whether race modifies the association between metformin use and prostate cancer aggressiveness remains uncertain. The association between metformin use and prostate cancer aggressiveness was examined separately in Black Americans (Blacks) and White Americans (Whites).

METHODS

The study population consisted of 305 Black and 195 White research participants with incident prostate cancer and self-reported diabetes from the North Carolina-Louisiana Prostate Cancer Project. High-aggressive prostate cancer was defined using a composite measure of Gleason sum, prostate-specific antigen, and clinical stage. Multivariable logistic regression was used to assess the association between metformin use and high-aggressive prostate cancer at diagnosis, separately among Whites and Blacks, with adjustment for age, screening history, site, education, insurance, and body mass index.

RESULTS

Metformin use was associated positively with high-aggressive prostate cancer in Blacks (OR 2.01; 95% CI 1.05, 3.83). By contrast, a weak inverse association between metformin use and high-aggressive prostate cancer was found in Whites (OR 0.80, 95% CI 0.34, 1.85).

CONCLUSIONS

The association between metformin use and prostate cancer aggressiveness may be modified by race.

A Comparison of the Use of Clinical-Guideline-Recommended Antihypertensive Regimens in Mexican American, Non-Hispanic Black, and Non-Hispanic White Adults With Type 2 Diabetes and Hypertension in the United States: NHANES 2003-2012

PURPOSE

The purpose of this study was to determine the use of clinical-guideline-recommended antihypertensive regimens among Mexican Americans (MAs) and non-Hispanic blacks and whites with type 2 diabetes and hypertension.

METHODS

A secondary data analysis based on National Health and Nutrition Examination Survey 2003-2012 cohort data included 1857 noninstitutionalized civilian MA, black, and white adults with type 2 diabetes and hypertension. Unadjusted and adjusted 2-way analysis of variance models evaluated whether there was a difference in the use of recommended antihypertensive regimens across race/ethnic group.

RESULTS

There was no difference in the use of recommended regimens across race/ethnic group (MAs, 79.1%; blacks, 81.7%; whites, 82.3%). Similarly, there was no difference between blood pressure goal levels and the use of recommended therapies across race/ethnicity (P = .632). Mexican Americans were least likely and blacks most likely to be on 3 or more antihypertensive drug classes (16.8% vs 28%). Furthermore, MAs were least likely to be on recommended add-on therapies such as calcium channel blockers and diuretics.

CONCLUSION

Racial/ethnic medication use disparities were observed when looking at the number of antihypertensive drug classes per patient regimen, and add-on therapy use was evaluated. Along with lifestyle modifications, frequent antihypertensive regimen reassessment is necessary.