Being overweight in midlife has been found to be associated with a statistically significant increase in cumulative burden of morbidity and health care costs during older adulthood compared with having a normal body mass index (BMI), a team of researchers reported in JAMA Network Open.
The investigators conducted a prospective study based on data from the Chicago Heart Association Detection Project in Industry (CHA) cohort, which enrolled 39,665 men and women aged 18 years and older from 1967 to 1973.
Eligible participants were alive and enrolled in Medicare after age 65 years. Medicare fee-for-service claims data from the US Centers for Medicare & Medicaid Services were obtained from January 1985 through December 2015.
Regarding the primary outcome, the investigators quantified all-cause morbidity in each year of follow-up using International Classification of Diseases, Ninth Revision codes to calculate the Gagne combined comorbidity score.
A total of 29,621 participants were included: mean (SD) age was 40 (12) years, 57.1% were men, 9.1% were Black, 46.0% had a normal BMI, 39.6% were overweight, and 11.9% had obesity classes I and II at baseline. A subgroup had available data from age 65 years (n=23,342), of whom 94.5% (n=22,058) had a Gagne morbidity score of 0 at age 65 years.
The cumulative morbidity burden according to Gagne score was significantly higher, with a dose-response association observed in each excess BMI category of being overweight (7.22 morbidity years), having obesity classes I and II (9.80 morbidity years), and having obesity class III (10.32 morbidity years) compared with having a normal BMI (6.10 morbidity years; adjusted P <.001 for all comparisons).
The cumulative cardiovascular disease morbidity burden was significantly increased, with a dose-response association found in each excess BMI category of being overweight (3.84 morbidity-years), having obesity classes I and II (5.02 morbidity-years), and having obesity class III (4.15 morbidity-years) vs having a normal BMI (2.88; adjusted P <.001 for all comparisons).
Overall, 13,932 participants (47.0%) died during the follow-up period, with a similar mean age at death occurring in those who were overweight (82.1 years [95% CI, 81.9-82.2]) and of younger age for those with obesity classes I and II (80.8 years [95% CI, 80.5-81.1]) and obesity class III (77.7 years [95% CI, 76.2-79.1]) compared with individuals with a normal BMI (82.3 years [95% CI, 82.1-82.5]).
The proportion (SE) of life-years lived in older adulthood for participants with a Gagne score of ≥1 was 0.38% (0.00%) in those who had a normal BMI, 0.41% (0.00%) in those who were overweight, and 0.43% (0.01%) in those with obesity.
The cumulative excess costs after age 65 years were higher for individuals who were overweight in midlife by a median of $12,390 (95% CI, $10,427-$14,354) and for those with obesity classes I and II in midlife by a median of $23,396 (95% CI, $18,474-$28,319), relative to individuals with a normal BMI in midlife.
The researchers noted that study participants were predominantly White and recruited from 1967 to 1973, with follow-up beginning in 1985. Also, the study excluded individuals who died at an age younger than 65 years, those who did not enroll in Medicare, and those with missing covariates.
“This study’s findings suggest that overweight status beginning in midlife is associated with long-term adverse health and economic consequences in the context of similar longevity,” the researchers stated.
Disclosure: One of the study authors declared an affiliation with a pharmaceutical company. Please see the original reference for a full list of authors’ disclosures.
Khan SS, Krefman AE, Zhao L, et al. Association of body mass index in midlife with morbidity burden in older adulthood and longevity. JAMA Netw Open. 2022;5(3):e222318. doi:10.1001/jamanetworkopen.2022.2318