Racial/ethnic disparities in association between dietary quality and incident diabetes in postmenopausal women in the United States: the Women's Health Initiative 1993–2005

Abstract

Objective. To examine the association of dietary quality and risk of incident diabetes overall and by race/ethnicity among postmenopausal women enrolled in the Women's Health Initiative (WHI).

Research methods and procedures. The WHI recruited 161,808 postmenopausal women between 1993 and 1998, and followed them until 2005. Incident diabetes was determined annually over an average of 7.6 years from enrollment. At baseline, all participants completed a Food Frequency Questionnaire (FFQ). Dietary quality was assessed by the Alternate Healthy Eating Index (AHEI), calculated from the baseline FFQ responses.

Results. There were 10,307 incident cases of self-reported treated diabetes over 1,172,761 person-years of follow-up. Most participants did not meet the AHEI dietary goals; that is, only 0.1% of women met or exceeded the recommended consumption of vegetables, and few (17.3%) met or exceeded the recommended level for total fiber. After adjusting for potential confounders, women in the highest quintile of the AHEI score were 24% less likely to develop diabetes relative to women in the lowest quintile of AHEI [hazard ratio (HR) = 0.76 (95% CI: 0.70–0.82)]. This association was observed in Whites [HR = 0.74 (95% CI: 0.68–0.82)] and Hispanics [HR = 0.68 (95% CI: 0.46–0.99)], but not in Blacks [HR = 0.85 (95% CI: 0.69–1.05)] or Asians [HR = 0.88 (95% CI: 0.57–1.38)].

Conclusion. These findings support a protective role of healthful eating choices in reducing the risk of developing diabetes, after adjusting for other lifestyle factors, in White and Hispanic postmenopausal women. Future studies are needed to investigate the relationship between dietary quality and risk of diabetes among Blacks and Asians in relationship to other lifestyle factors.

Keywords:

• dietary quality
• diabetes
• postmenopausal women
• women's health
• epidemiology

Acknowledgements

Yunsheng Ma, Yongxia Qiao and Lesley Tinker designed the research and drafted the manuscript; Yongxia Qiao and Raji Balasubramanian analyzed data; Barbara C. Olendzki, James R. Hébert, Raji Balasubramanian, Milagros C. Rosal, Kristin L. Schneider, Simin Liu, Stacy Sims, Melanie Hingle, Yiqing Song, Judith K. Ockene, Deidre M. Sepavich, James M. Shikany, and Gioia Persuitte, reviewed and provided feedback to the manuscript; all authors read and approved the final manuscript. The authors thank the principal investigators of all WHI clinical centers and the data coordinating center for their contribution to the study. They are indebted to the dedicated and committed participants of the WHI. This research was supported by the National Heart, Lung, and Blood Institute (NHLBI) grant No. 1R01HL094575–01A1 to Dr Yunsheng Ma. It was also supported in part by Center Grant 5 P30 DK32520 from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Drs. Yunsheng Ma and Milagros C. Rosal are members of the University of Massachusetts Medical School Diabetes and Endocrinology Research Center (DERC) (DK32520). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIDDK or NHLBI. The Women's Health Initiative (WHI) program is funded by the NHLBI, National Institutes of Health, US Department of Health and Human Services through contracts N01WH22110, 24152, 32100–2, 32105–6, 32108–9, 32111–13, 32115, 32118–32119, 32122, 42107–26, 42129–32, and 44221.