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Impact of Body Mass Index and Metabolic Health Status on All‐Cause Mortality Risk among Older Adults
Author(s) -
Cheng Feon W.,
Gao Xiang,
Mitchell Diane C.,
Wood Craig,
Still Christopher,
Jensen Gordon L.
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.417.1
Subject(s) - medicine , body mass index , hazard ratio , overweight , obesity , proportional hazards model , cohort , demography , confidence interval , gerontology , sociology
Reduced all‐cause mortality has been reported for older persons with overweight or class I obesity (body mass index, BMI 25.0–29.9 or 30.0–34.9 kg/m 2 , respectively) compared to those of desirable BMI (18.5–24.9 kg/m 2 ). The explanation for this observation remains unclear. Our objective was to investigate the joint effects of BMI and metabolic health status on all‐cause mortality in a well characterized cohort of advanced age. Methods Among 4,551 older adults with a mean age of 74 ± 4.7 years at baseline, we categorized individuals into eight groups according to BMI categories (18.5–24.9, 25.0–29.9, 30.0–34.9, and ≥35.0 kg/m 2 ) and the presence or absence of a metabolically healthy phenotype, defined as having 0 or 1 of the metabolic risk factors based on a modified Adult Treatment Panel III guideline proposed by the National Cholesterol Education Program. Metabolically unhealthy was 2 or more risk factors. A Cox proportional hazards model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for age, sex, smoking, alcohol, laboratory values, and comorbidity status. Results There were 2,294 mortality cases over a mean 10.9 years of follow up. Compared to metabolically healthy persons of desirable BMI 18.5–24.9 kg/m 2 , metabolically unhealthy participants of all BMI groups had increased risk of all‐cause mortality ( Figure 1). Compared with metabolically healthy BMI 18.5–24.9 kg/m 2 individuals, their metabolically healthy overweight and obesity class I counterparts were not at greater all‐cause mortality risk (HR, 0.89; 95 CI%, 0.74–1.06 and HR, 0.75; 95 CI%, 0.59–0.94, respectively) ( P‐Interaction : 0.03, Figure 1). Conclusions Among older adults, metabolically healthy overweight or mild obesity (class I) is not associated with a higher mortality risk and unhealthy metabolic status may be a risk factor for all‐cause mortality regardless of BMI group. It appears that metabolically healthy overweight and mildly obese persons of advanced age account for the “obesity paradox”. Support or Funding Information Supported by United States Department of Agriculture, Agricultural Research Service, 8050‐51530‐012‐01A.