Piras D, Masala M, Delitala A, et al. - Using a population-based sample of 3,972 Sardinians (age range 18–100 years), researchers examined the link of kidney size to ageing, kidney function and kidney disease risk factors. Among participants, ultrasound length and parenchymal kidney volume were ascertained. To describe age- and gender-specific reference ranges (2.5–97.5 percentile) of kidney volume, the subset of 2,256 ‘healthy’ individuals was identified. A rise in kidney volume and length was observed in the healthy subset up to the fourth to fifth decade of life followed by a progressive reduction in males, whereas a slow kidney volume reduction throughout the lifespan of women was noted. In the entire sample, male gender, low body mass index, short height, low waist:hip ratio and high serum creatinine (SCr) were identified as independent predictors of lower kidney volume (< 2.5 percentile for age and gender); larger kidney volume (> 97.5 percentile for age and gender) was independently predicted by younger age, female gender, diabetes, obesity, high height, high waist:hip ratio and lower SCr. Heritability for kidney volume and for length was estimated to be 15% and 27%, respectively; a strong correlation of kidney volume with birthweight was identified. Findings revealed disparities in the observed kidney measures' decline with age between men and women in a general healthy population. Genetic factors and modifiable clinical factors constituted the determinants of kidney parenchymal volume.