Early-Life Factors as Predictors of Age-Associated Deficit Accumulation Across 17 Years From Midlife Into Old Age

Abstract

Background Early life exposures have been associated with the risk of frailty in old age. We investigated whether early life exposures predict the level and rate of change in a frailty index (FI) from midlife into old age. Methods A linear mixed model analysis was performed using data from three measurement occasions over 17 years in participants from the Helsinki Birth Cohort Study (n=2000) aged 57-84 years. A 41-item FI was calculated on each occasion. Information on birth size, maternal body mass index (BMI), growth in infancy and childhood, childhood socioeconomic status (SES), and early life stress (wartime separation from both parents), was obtained from registers and healthcare records. Results At age 57 years the mean FI level was 0.186 and the FI levels increased by 0.34 percent/year from midlife into old age. Larger body size at birth associated with a slower increase in FI levels from midlife into old age. Per 1kg greater birth weight the increase in FI levels per year was -0.087 percentage points slower (95% CI=-0.163, -0.011; p=0.026). Higher maternal BMI was associated with a higher offspring FI level in midlife and a slower increase in FI levels into old age. Larger size, faster growth from infancy to childhood, and low SES in childhood were all associated with a lower FI level in midlife but not with its rate of change. Conclusions Early life factors seem to contribute to disparities in frailty from midlife into old age. Early life factors may identify groups that could benefit from frailty prevention, optimally initiated early in life.

The brain insulin receptor gene network and associations with frailty index

“…The FI × 100 level of ≥25 was used to indicate frail state [ 8 , 41 ]. The HBCS-FI has been found to share similar characteristics with other published studies applying the FI [ 40 ].…”

“…The HBCS-FI was created according to standard procedures [ 38 ] based on the Rockwood deficit accumulation model [ 39 ] and calculated for each of the three measurement occasions as previously described [ 40 ]. We considered symptoms, diseases, disabilities, clinical measurements and laboratory test results.…”

“…Co-variates included smoking, adult socioeconomic factor (SES) and birth weight. Smoking and SES were selected based on previous literature [ 40 ], while birthweight was chosen due to its possible impact on ePRS-IR. Smoking was coded as never, former and current.…”

Body Composition in Late Midlife as a Predictor of Accelerated Age-associated Deficit-accumulation From Late Midlife into Old Age: A Longitudinal Birth Cohort Study

“…The resulting 39-item FI was used for our analyses; the 39 items and their scoring into deficits can be found in Supplementary Table 1. The FI could be calculated for 99.6%, 99.9%, and 99.1% of participants participating at each consecutive clinical visit, respectively (13). A total of 2000 participants had data on FI available from at least one clinical measurement occasion.…”

“…We were able to study lean and fat mass indices separately and jointly to further our understanding on the association between body composition and frailty. The FI (13) used in the study emphasises weight loss less (one of the 39 deficits) than the frailty phenotype (one of five criteria), which may help to reduce confounding between body composition and frailty. The study results should be interpreted considering the following weaknesses.…”