- Among older African-American patients with type 2 diabetes (T2DM), those having the haptoglobin (HP) 1-1 genotype had poorer baseline cognitive function and more rapid decline over time.
Why this matters
- Dementia risk is higher for blacks than for whites, but genetic contributors to this disparity are still being elucidated.
- Genotype prevalences:
- 29.4% for Hp 1-1.
- 36.1% for Hp 2-1.
- 10.9% for Hp 2-1m.
- 23.6% for Hp 2-2.
- Baseline Mini-Mental State Examination (MMSE) scores:
- Differed across 4 genotype groups (P=.006).
- Lowest with Hp 1-1 (mean, 25.68).
- Highest with Hp 2-1m (mean, 27.15).
- 40-month decline in MMSE score:
- Significant for Hp 1-1 (mean, −0.41; P=.04).
- Significant for Hp 2-2 (mean, −0.68; P=.001).
- Not significantly different across 4 genotype groups.
- Interaction of age with genotype on MMSE score:
- Significant for Hp 1-1 genotype (mean annual decline, −0.87; P=.005).
- Not significant for other genotypes.
- Multicenter cohort study of 466 older African-American patients (mean age, 62.3 years) with T2DM from the ACCORD-MIND study.
- Genotypes assessed from serum samples.
- Main outcome: cognitive function (MMSE).
- Funding: National Institute on Aging.
- Unclear generalizability.
- Potential survivor bias.