OP69 The association between birth weight and grip strength at age 60: The Newcastle thousand families study

Background

Multiple studies have been carried out to investigate the link between birth weight and grip strength. These previous studies suggest an association between low birth weight and reduced grip strength. However, the majority of these focussed on grip strength in younger adults. Muscle mass decreases at around 3–8% per decade after the age of 30, and declines even more after the age of 60. This study aimed to assess the association between birth weight and grip strength at age 60 years in the Newcastle Thousand Families Study (NTFS) birth cohort.

Methods

The NTFS was established in1947 when all 1142 babies born in May and June of that year in the city of Newcastle upon Tyne, were recruited. Detailed data were collected, prospectively, including birth weight, gestational age, duration breast fed and social class throughout childhood, with later follow-ups during adulthood. Grip strength and adult height were measured when the study members were ages 61–63 years old. The data were analysed using linear regression and path analysis, with adjustment for potential confounders such as sex and social class at birth and assessment of potential mediation.

Results

Of the original cohort, 351 (91 female, 160 male) were included in the analysis, with complete data on birth weight and grip strength. A significant association between higher birth weight and increased grip strength at age 60 was found (coefficient 3.94 (95% confidence interval (CI) 2.00,5.88) p<0.001). Results remained significant after adjusting for sex (coefficient 2.60 (95% CI 1.32,3.87) p<0.001) and social class at birth (coefficient 3.89 (95% CI 1.89, 5.89) p<0.001). There was evidence of mediation of some of the effect of birthweight on later grip strength, achieved through adult height.

Conclusion

Grip strength at age 60 can be associated with multiple variables including birthweight, which can be seen to be a predictor of grip strength later in life. This could also suggest that birth weight could be associated with general health status, particularly muscle atrophy, later in life. Research in this area should continue, to explore further the relationship between birth weight, grip strength and health of individuals later in life.