Mohammad Mohammadi - Department of Community Medicine, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
Roya Sakhaei - Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Azadeh Nadjarzadeh - Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Akram Esmaeili - Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Roya Hemayati - Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Javad Zavar Reza - Department of Medical Biochemistry, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Hassan Mozaffari-Khosravi - Yazd Diabetic Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Nahid Ramezani-Jolfaie - Department of Community Medicine, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.

Background: Hibiscus sabdariffa linnaeus (HSL) is a tropical plant with a high content of anthocyanin, traditionally found to have beneficial biological activities. This randomized, double-blind, placebo-controlled, and parallel trial was conducted to assess some renal and cardiovascular effects of supplementation with HSL in patients with diabetic nephropathy. Methods: The study protocol was completed by ۶۰ patients (۳۸ females and ۲۲ males) who were randomly assigned into the supplemented (SG) and Placebo groups (PG). The SG was treated with ۴۲۵ mg of HSL twice daily and the PG received the placebo. Anthropometric and dietary information as well as fasting blood and urine samples were collected at the baseline and end of an ۸-week intervention period. Results: Compared with the PG, supplementation with HSL significantly reduced systolic blood pressure (P = ۰.۰۱) and high-sensitivity C-reactive protein (P = ۰.۰۰۴). A significant increase was observed in total antioxidant capacity levels in the SG (P = ۰.۰۳). Moreover, we found a significant reduction in the levels of blood urea nitrogen (P < ۰.۰۰۱), blood creatinine (P = ۰.۰۰۲), urine creatinine (P < ۰.۰۰۱), and urine albumin (P < ۰.۰۰۱) in the SG compared with the PG. However, no significant change was observed in diastolic blood pressure, fasting blood glucose, and glomerular filtration rate following intervention between two groups. Conclusions: HSL supplementation seems to be beneficial in improving the outcomes of patients with diabetic nephropathy; however, no considerable effect was observed on fasting glucose levels. Large-scale trials are needed to better understand its efficiency and safety for long-term use.

Hibiscus sabdariffa, Diabetic nephropathies, Lipids, Blood pressure.