Ramadan fasting in Saudi Arabia is associated with altered expression of CLOCK, DUSP and IL-1alpha genes, as well as changes in cardiometabolic risk factors

RESEARCH ARTICLE Ramadan fasting in Saudi Arabia is associated with altered expression of CLOCK, DUSP and IL-1alpha genes, as well as changes in cardiometabolic risk factors Ghada M. A. Ajabnoor1,2, Suhad Bahijri1,2*, Noor Ahmad Shaik3,4, Anwar Borai2,5, Aliaa A. Alamoudi1,2, Jumana Y. Al-Aama2,3,4, George P. Chrousos2,6 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia, 2 Saudi Diabetes Study Research Group, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia, 3 Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia, 4 Princess Al-Jawhara Al-Brahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia, 5 King Abdullah International Medical Research Center (KAIMRC), College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Jeddah, Saudi Arabia, 6 First Department of Pediatrics, University of Athens Medical School,‘‘Aghia Sophia” Children’s Hospital, Athens, Greece * OPEN ACCESS Citation: Ajabnoor GMA, Bahijri S, Shaik NA, Borai A, Alamoudi AA, Al-Aama JY, et al. (2017) Ramadan fasting in Saudi Arabia is associated with altered expression of CLOCK, DUSP and IL-1alpha genes, as well as changes in cardiometabolic risk factors. PLoS ONE 12(4): e0174342. https://doi. org/10.1371/journal.pone.0174342 Editor: Henrik Oster, University of Lübeck, GERMANY Abstract Background During the fasting month of Ramadan, practicing Saudis develop severe disturbances in sleeping and feeding patterns. Concomitantly, cortisol circadian rhythm is abolished, diurnal cortisol levels are elevated and circulating levels of several adipokines are altered favouring insulin resistance. Received: September 5, 2016 Accepted: March 7, 2017 Aim Published: April 6, 2017 To examine changes in the expression of CLOCK and glucocorticoid-controlled genes, such as DUSP1 and IL-1α in Saudi adults before and during Ramadan, and to investigate possible associations with selected cardiometabolic risk factors. Copyright: © 2017 Ajabnoor et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The funding body is Deanship of Scientific Research, (DSR) at King Abdulaziz University – Jeddah- Kingdom of Saudi Arabia under grant number (HiCi/1432- 6-2), URL: http:// dsr.kau.edu.sa/Default.aspx?Site_ID=305&Lng= AR. Given that no individuals employed or contracted by the funder, other than the authors, Methods Healthy young volunteers (5 females, 18 males; mean age +SEM = 23.2 +1.2 years) were evaluated before Ramadan and two weeks into it. Blood samples were collected at 9 am (±1 hour) and twelve hours later for determination of serum lipid profile, high sensitivity CRP (hsCRP), and adiponectin. The expression of CLOCK, DUSP1 and IL-1α was evaluated in circulating leukocytes. Results Mean levels of GGT and morning adiponectin decreased, while those of LDL-c/ HDL-c and atherogenic index (AI) increased significantly in Ramadan compared to Shabaan. There PLOS ONE | https://doi.org/10.1371/journal.pone.0174342 April 6, 2017 1 / 12 Ramadan fasting in Saudi Arabia is associated with altered cardiometabolic risk factors were involved in these tasks and the authors had unrestricted access to the data, we declared that the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. was no significant difference between morning and evening adiponectin during Ramadan, while the diurnal rhythm of hsCRP was lost. CLOCK gene expression mean was significantly higher in morning than in evening during Shabaan. Mean morning and evening DUSP1 mRNA levels showed significant increase during Ramadan compared to Shabaan, however, its diurnal rhythm was maintained. Morning IL-1α mRNA expression remained significantly higher than in the evening during Ramadan, but was markedly decreased compared to Shabaan. Discussion Ramadan fasting in Saudi Arabia is associated with improvements in some cardiometabolic risk factors, such as circulating GGT and hsCRP and leukocyte expression of IL-1α mRNA, suggesting that intermittent fasting might have a beneficial component. These benefits may be offset by the previously reported dysregulation in the circadian rhythm, excess glucocorticoid levels and action, and insulin resistance, explaining increased prevalence of cardiometabolic disorders and type 2 diabetes mellitus. Introduction Circadian rhythms control many physiologic processes, including energy metabolism, hormone biosynthesis, and immune responses. It is estimated that approximately 10% of the main transcriptome in mammalian cells is expressed with a circadian rhythm. Indeed, studies examining the physiologic effects of sleep restriction, reported changes in the circadian timing system [1], as well as immune [2] and endocrine [3, 4] variables. In the recent years, the molecular mechanisms that control the circadian rhythm, also known as the “molecular clock”, have been identified [5]. These consist of a series of interlocked transcriptional-translational feedback loops, with one of the major loops being the CLOCK/BMAL1 loop [6, 7]. Circadian clock genes are expressed in a circadian fashion in the suprachiasmatic nucleus (SCN) of mammals, constituting the “master” circadian pacemaker of the organism. The important link between the CLOCK gene and intermediary metabolism has been shown in CLOCK knock-out mice, which have impaired glucose tolerance and insulin secretion, resulting in a diabetic phenotype [8]. Current work suggest a major role for shift-work induced alterations in core circadian clock genes [9, 10] in disrupting circadian metabolic regulation, and in inducing various shiftwork associated diseases [11–13]. In a similar manner to shift workers, during the fasting month of Ramadan, Muslims in Saudi Arabia experience severe disturbance in their sleeping patterns, with loss of night-time sleep and shortening of sleep duration. This can be associated with the loss of the circadian rhythm of cortisol, a hormone that controls the expression of many other hormones, and cytokines including adipokines [14]. This loss of circadian rhythmicity might be related to alterations in the expression of clock genes, resulting in hypercortisolism and chronic smoldering inflammation, increasing the risk of chronic cardiometabolic disorders. One of many important genes upregulated by cortisol is the Dual Specific Phosphatases (DUS (...truncated)