We did not see previously reported associations of several clinical and biochemical phenotypes with BP dipping, for example, diabetes mellitus, obesity, CRP, renal function (estimated glomerular filtration rate) and urinary salt excretion.14, 15, 31, 32, 33, 34 A likely explanation is that most of the previous studies have been undertaken in patients with hypertension and/or end organ damage,3, 15, 34, 35, 36, 37 where some of the variables (for example, CRP and estimated glomerular filtration rate) may show a broader range. This evidence concerns the gene CRP and obesity due to melanocortin 4 receptor deficiency.