Obesity and 10-year mortality in very old African Americans and Yoruba-Nigerians: exploring the obesity paradox.
BACKGROUND
To compare the effect of obesity and related risk factors on 10-year mortality in two cohorts of older adults of African descent; one from the United States and one from Nigeria.


METHODS
Study participants were community residents aged 70 or older of African descent living in Indianapolis, Indiana (N = 1,269) or Ibadan, Nigeria (1,197). We compared survival curves between the two cohorts by obesity class and estimated the effect of obesity class on mortality in Cox proportional hazards models controlling for age, gender, alcohol use, and smoking history, and the cardiometabolic biomarkers blood pressure, triglycerides, high-density lipoprotein, low-density lipoprotein, and C-reactive protein.


RESULTS
We found that underweight was associated with an increased risk of death in both the Yoruba (hazards ratio = 1.35, 95% confidence interval: 1.12-1.63) and African American samples (hazards ratio = 2.49, 95% confidence interval: 1.40-4.43) compared with those with normal weight. The overweight and obese participants in both cohorts experienced survival similar to the normal weight participants. Controlling for cardiometabolic biomarkers had little effect on the obesity-specific hazard ratios in either cohort.


CONCLUSIONS
Despite significant differences across these two cohorts in terms of obesity and biomarker levels, overall 10-year survival and obesity class-specific survival were remarkably similar.
daniclar@iupui.edu.
Daniel O
DO
Clark
Department of Biostatistics, Indiana University School of Medicine, Indianapolis.
Sujuan
S
Gao
Department of Biostatistics, Indiana University School of Medicine, Indianapolis.
Kathleen A
KA
Lane
Christopher M
CM
Callahan
Department of Psychiatry and.
Olusegun
O
Baiyewu
Department of Medicine, College of Medicine, University of Ibadan, Nigeria.
Adesola
A
Ogunniyi
Department of Medicine, Indiana University Center for Aging Research, Indianapolis. Department of Medicine, Regenstrief Institute, Inc., Indianapolis, Indiana. Department of Psychiatry, Indiana University School of Medicine, Indianapolis.
Hugh C
HC
Hendrie
D001741:Black or African American; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D044383:Black People; D001794:Blood Pressure; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006801:Humans; D007196:Indiana / Q000453:epidemiology; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D009549:Nigeria / Q000453:epidemiology; D009765:Obesity / Q000453:epidemiology / Q000401:mortality*; D012907:Smoking / Q000453:epidemiology; D014280:Triglycerides / Q000097:blood
D015415:Biomarkers; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002097:C-Reactive Protein
African; Biomarkers.; Mortality; Obesity; Older adults