Renal morphology assessed by ultrasound in relation to central haemodynamics and body fat

There is a correlation between renal function and the morphological characteristics of the kidney. However, little is known about the association between renal morphology and other important predictors of the risk of cardiovascular diseases, such as central haemodynamics or body fat. Thus, in the present study we investigated correlations between renal morphology, body fat and central haemodynamics. Renal morphology and intra-abdominal and subcutaneous fat were assessed by ultrasound, whereas central haemodynamics were evaluated by pulse wave analysis, in 93 healthy, non-obese subjects (mean (±SEM) age 52 ± 1 years; 43 men, 50 women). Significant correlations were found for indices of body fat (waist : hip ratio, body mass index and intra-abdominal fat) and renal morphology (kidney length, width and volume). Significant inverse correlations were found between central augmentation pressure (cAP) and kidney length (r = -0.33; P = 0.0009), width (r = -0.24; P = 0.01) and volume (r = -0.27; P = 0.007). In addition, significant negative correlations were found between the central augmentation index (cAIx) and kidney length (r = -0.36; P = 0.0003), width (r = -0.29; P = 0.003) and volume (r = -0.33; P = 0.0008). Multiple linear regression analysis revealed independent associations between kidney length and both cAP and cAIx. In conclusion, common morphometric characteristics of the kidney, as assessed by ultrasound, are associated with measures of body fat and descriptors of central haemodynamics. The relationships demonstrated in the present study indicate that these associations may be a biologically plausible phenomenon.