Background: Grip strength predicts long-term morbidity and mortality in adults. We compared grip strength in adults born with extremely low birth weight (ELBW; under 1 kg) and a normal birth weight control group (NBW) and describe change in grip strength over a 10-year period in a longitudinal cohort study of preterm birth.
Methods: Grip strength, body composition, and device-measured physical activity were assessed in 95 mature adults (MA) born ELBW (age 31.6 (1.6) mean (SD) years, 59 females) and 88 born NBW (age 31.9 (1.4) years, 52 females). Regression models were used to examine the effect of perinatal factors, body composition, physical activity, and physical self-efficacy on grip strength.
Results: Grip strength was lower in MA born ELBW compared to NBW (31.8 (10.0) vs. 39.8 (11.2) kg; p < 0.001). Birth weight group was associated with grip strength independent of sex, height, and lean mass index, but device-measured physical activity was not. The change in grip strength from mid-20s to MA was similar in ELBW and NBW participants.
Discussion: Grip strength in MA born ELBW is low and is similar to a reference group 25-30 years older, suggesting higher risk for cardiovascular and all-cause mortality.
Impact: Adults born extremely preterm have reduced grip strength compared to control participants born at full term. Reduced grip strength is a predictor of frailty and increased cardiovascular disease risk. Change in grip strength from age in mid-20s to mid-30s is similar in those born preterm and full-term-born controls. Grip strength is related to lean mass and not to device-measured physical activity-and correlates of grip strength are similar in those born preterm and term-born controls. Grip strength is a simple measure that may provide information about the health of adults born preterm.