Diabetes: (Hp) 1-1 genotype Less Favorable Cardiac, Cognitive Profiles

MedicalResearch.com Interview with:

Ramit Ravona-Springer M.D., Psychiatrist
Director of Memory Clinic,
Sheba Medical Center, Tel Hashomer, Israel

MedicalResearch.com: What are the main findings of the study?

Answer: In a cohort of elderly, cognitively normal type 2 diabetes (T2D) subjects, those with Haptoglobin (Hp) 1-1 genotype present lower cognitive performance compared to Hp 2 carriers (Hp 1-2 and Hp 2-2). The contribution of cardiovascular risk factors to cognition was significantly higher in subjects with Hp1-1 genotype compared to Hp 2 carriers.

MedicalResearch.com: Were any of the findings unexpected?

Answer: Previous studies have shown that Hp 2-2 genotype is associated with a less favorable cardiovascular profile. Since the latter is associated with cognitive function, Hp 2 allele could be expected to be associated with lower cognitive performance. However, the role of Hp in vascular pathology may differ according to the vascular bed (brain versus periphery): the frequency of Hp 1-1 genotype was significantly higher and frequency of Hp 2 allele was significantly lower in a cohort of subjects with first symptomatic lacunar stroke due to small vessel disease compared to their frequency in healthy controls.

MedicalResearch.com: What should clinicians and patients take away from your report?

Answer: Hp genotype may be considered in the future as a factor that is associated with cognitive outcomes of T2D. Nevertheless, the results cannot yet be implemented since they are based on cross sectional data. We cannot rule out that these results reflect an artifact of the selection of subjects.  Hp 2 carriers, who tend to have more cardiovascular disease, might  have had higher mortality, morbidity, or cognitive impairment that precluded their participation in the study. The longitudinal follow up of this sample is essential to shed light on this potential limitation and the interpretation of the current results.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Answer: Future studies should study the association of Hp genotype with rate of cognitive decline, risk for Mild Cognitive Impairment and dementia and the modifying effect of T2D characteristics on this association.

Citation:

Haptoglobin 1-1 Genotype Is Associated With Poorer Cognitive Functioning in Type 2 Diabetic Elderly

Ramit Ravona-Springer, Anthony Heymann, James Schmeidler, Elizabeth Guerrero-Berroa, Mary Sano, Rachel Preiss, Keren Koifman, Hadas Hoffman, Andrew Levy, Jeremy M. Silverman, and Michal Schnaider-Beeri

 Diabetes Care published ahead of print August 29, 2013, doi:10.2337/dc12-2250