Integrating Sleep Disruption, Dietary Changes, and Therapy in Assessing the Effects of Ramadan Fasting on Blood Pressure

Dear Editor, We have read with great interest the article by Tezcan and Büyükterzi on the effect of Ramadan fasting on blood pressure and kidney function in newly diagnosed hypertensive patients [1]. The study contributes valuable data on a unique and culturally relevant context. However, we would like to raise several methodological and interpretative issues that may affect the generalizability of the conclusions. The retrospective design and single-center setting may limit the strength of causal inferences. Previous studies have emphasized that prospective, multicenter cohorts are better suited to capture the heterogeneous impact of fasting across different populations [2]. The authors acknowledge this limitation, but its implications deserve stronger emphasis, particularly considering dietary, lifestyle, and medication adherence variability. All patients in the study received a diuretic-containing regimen. While this provides uniformity, it restricts external validity. Other antihypertensive classes, such as calcium channel blockers or beta-blockers, may interact differently with fasting physiology. Dietary sodium intake and hydration patterns that strongly influence blood pressure and renal function were not systematically assessed. Prospective trials with structured food-frequency questionnaires and biochemical markers have shown that these parameters substantially modify outcomes during Ramadan [3]. Neglecting them may underestimate important confounders. Therefore, it remains uncertain whether the findings apply broadly to hypertensive patients treated with varied regimens. Another important factor that warrants attention is the alteration of sleep patterns during Ramadan. The practice of waking up for suhoor (pre-dawn meal) often leads to fragmented nocturnal sleep and daytime somnolence. Disrupted circadian rhythms are known to influence blood pressure variability and autonomic balance, potentially confounding the observed outcomes [4]. Since sleep quality was not evaluated in the present study, its interaction with blood pressure and kidney function during fasting remains uncertain. Although the authors report no significant deterioration in kidney function, longer follow-up is essential. Renal adaptation to repeated annual fasting periods may differ from short-term observations. Indeed, longitudinal studies highlight that subtle cumulative effects may only emerge over years rather than a single month [5]. In conclusion, this article provides a useful foundation for understanding Ramadan fasting in newly diagnosed hypertensive patients, but further prospective, multicenter, and regimen-diverse studies—also accounting for sleep patterns and lifestyle changes—are warranted to establish robust clinical recommendations. Sincerely, Mucahit Yetim, Abdullah Sarıhan, and Macit Kalçık Department of Cardiology, Faculty of Medicine, Hitit University, Corum, Turkey All of the authors contributed to planning, writing, and revision. The authors declare that they have no conflict of interest.