Birthweight and Glucose Tolerance Status Are Associated With Organ Sizes in Older Adults

ABSTRACT Aims Low birthweight is a risk factor of Type 2 diabetes and cardiovascular disease. Organ size is related to organ function and disease, but few studies have examined cardiometabolic organ sizes in relation to birthweight and glucose tolerance. This longitudinal follow‐up study investigated whether organ size varied by birthweight and/or glycaemic status in an elderly population. Methods and Materials 1212 participants aged 53–83 years from the Danish Inter99 20‐year follow‐up study, with original midwife birthweight records, underwent computed tomography imaging. Linear regression was used to examine associations between birthweight and organ sizes, and differences in organ sizes across normoglycaemic, prediabetes and diabetes groups. Results After adjustment for sex, age, birth year, preterm birth and body surface area, a 1 kg lower birthweight was associated with a 2.0% (95% CI: 0.1%, 3.9%) lower kidney volume and a 3.8% (95% CI: 1.2%, 6.5%) lower lung volume, and with a 3.9% (95% CI: 0.3%, 7.5%) larger adrenal gland volume. Further adjustment for subcutaneous and visceral adipose tissue attenuated the lung association. Compared with normoglycaemic participants, individuals with prediabetes and/or diabetes showed larger liver, kidney and adrenal gland volumes, whereas pancreas volume was smaller, adjusted for birthweight and body size. Conclusion Lower birthweight was associated with smaller kidneys, and to some extent lungs, and with larger adrenal glands, whereas diabetes and prediabetes were associated with larger kidney, liver and adrenal glands, and with lower pancreas volumes. Further studies are needed to understand the clinical and/or physiological implications of these findings. Trial Registration NCT05166447