This study shows a significant improvement in 10
years coronary heart disease risk, based on Framingham risk score.To the best of our knowledge, there was no similar study among cardiovascular patients to assess the effect of Ramadan fasting on cardiovascular risks. Most of the studies evaluated changes of some cardiovascular risk factors among metabolic syndrome, diabetic, hyperlipidemic patients and or healthy adults.
There was a significant higher HDL-c and lower cholesterol, triglycerides, LDL-c, VLDL-c levels, cholesterol/HDL and LDL/HDL ratios after Ramadan in the present study. In Helsinki Heart Study a 10% reduction in TC, LDL-c (11%), 35% decrease in triglycerides and 11% increase in HDL-c after the intervention with pharmacological agent was associated with a 34% reduction in cardiovascular event [28
]. A 2 unit increment of TC/HDL adds an excess of 68% to CHD risk [27
]. Our study demonstrates significant improvement (−0.6) in TC/HDL and other lipids profile after Ramadan fasting which might be associated with a nearly 20% reduction in the risk of CHD.
A reduction in cholesterol [30
], and triglycerides levels [30
], has been reported in previous studies; however, The result of some other reports showed no significant changes in cholesterol [1
] and triglycerides [1
]. In a study in Kuwait on sixteen sedentary healthy adult males, there was no significant change in TG level after Ramadan [33
]. This discrepancy was possibly due to small sample size or different Ramadan diet pattern in Kuwait study which includes more sweetened foods. Also, there are some reports about increased cholesterol [10
] and triglycerides [10
] after Ramadan fasting. There is a tendency for higher simple carbohydrate consumption during Ramadan [36
Improvement in HDL-c has been shown in somestudies after fasting in Ramadan [2
], while some other studies reported no significant change [1
] or decrease [9
] in HDL-c after Ramadan.
Significant decline in LDL-c has been reported in some studies after Ramadan fasting[2
]. Also, no significant change [1
] or significant increase [9
] of LDL-c has been reported in other investigations.
It seems that the effect of Ramadan fasting on serum lipid levels may be closely related to the dietary habits and other life style changes [2
There were significant decrease in systolic blood pressure and no significant change in diastolic blood pressures after Ramadan fasting in the present study. However, there are reports about significant decrease [1
], no significant change [9
] and significant increase [33
] in systolic blood pressure.
There was no significant change in FBS, fasting insulin and insulin-resistance (HOMA-IR) after Ramadan fasting in the present study. Some studies showed no significant changes in the serum level of glucose [1
]. While, the others reported higher [9
] or lower [2
] FBS after Ramadan fasting. These controversies may be explained by different food habits, amount of calorie intake [30
], the number of fasting days, period of daily fasting, time of sampling, genetic tendency and daily activity in different reports. There is a report about significant increase in insulin sensitivity (1/HOMA IR) in subjects with the metabolic syndrome [8
] and significant decrease in insulin and insulin resistance among men patients with type II diabetes after Ramadan fasting [35
]. The lack of improvement in HOMA-IR or FBS despite reduction in body weight may be due to decrease in total body water content instead of body fat content after Ramadan fasting.
The value of hcy level did not change significantly after Ramadan in the present study. Although, Aksungar's study has been reported significant decrease in hcy after Ramadan fasting in 40 healthy volunteers [12
Body weight and BMI decreased significantly in the present study (−1.4
kg and −0.7
kg/m2 respectively, P <
0.001). Most reports are similar to these results [31
]. Although, there are some reports about non-significant changes in body weight [37
] and BMI [37
] after Ramadan fasting.
In another study, no change was seen concerning anthropometric parameters [7
There was no control group in this study. Pre Ramadan sampling in Ramadan was performed in the morning after an overnight fasting, while post Ramadan blood sampling was performed in the afternoon, after at least 10
h fasting during day time. This difference in the time of blood sampling was inevitable to have at least 10
h fasting. As the circadian rhythms of nutrition-related biological variables shows some degree of changes during Ramadan [39
], there might be concerns about amount of daily activities or circadian rhythm of hormones like cortisol which might affect FBS levels. In the present study, we had only two measurements during the study, possibly evaluation in the middle of the month and after a time after Ramadan would reveal more details and shows us the trend of changes. Level of physical activity of the study population was not measured in this study. FFQ was completed for a control group not our subjects as this study was part of the bigger study that food data were completed as a separate study for a 500 volunteers to assess food pattern changes in Ramadan.
A multi-center study with larger sample size and other habitual changes controlled with matched control group is warranted.