Dear Editor,

Afsar et al. [1] concluded that the presence of simple renal cysts is related to higher ambulatory blood pressure and with non-dipping phenomenon in patients with essential hypertension. Evidence has been shown about association of hypertension and simple renal cysts [2]. The actual and independent association of simple renal cysts and non-dipping phenomenon in essential hypertension is still unclear from this study.

Non-dipping blood pressure profile is usually defined as a nocturnal BP fall of less than 10% [3]. Its association with salt-sensitive forms of hypertension, renal function impairment and mineralocorticoid-induced forms of hypertension has been postulated [3]. Evidence suggests that these confounding variables have to be taken into consideration before final conclusions can be drawn.

Furthermore, a larger sample size may help delineate these associations which would enhance the clinical and statistical significance of these findings.