An umbrella review and meta-analysis of meta-analyses of the impact of Ramadan fasting on the metabolic syndrome components

CONTEXT

Ramadan is a holy month of fasting, spiritual reflection, and worship for Muslims worldwide. However, the Ramadan fast - which involves abstaining from all food and drink, sunrise to sunset for 29 days-30 days annually - may also influence physical health outcomes, especially relating to the risk of metabolic syndrome.

OBJECTIVE

The literature from the top of the pyramid of evidence was gathered and synthesized for this comprehensive umbrella review and meta-analysis of meta-analyses in order to provide an overall conclusion on the impact of Ramadan fasting with regard to metabolic syndrome components.

DATA EXTRACTION

Eleven systematic reviews and meta-analyses were included in the current umbrella review. Nine components, including waist circumference, body weight), high-density lipoprotein, low-density lipoprotein, total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure), and fasting blood plasma glucose were analyzed.

DATA ANALYSIS

The random-effects meta-analysis results revealed standard mean differences as follows: waist circumference -0.30 (95% confidence interval [CI] -0.33 to -0.27), body weight -0.34 (95% CI -0.39 to -0.29), high-density lipoprotein 0.20 (95% CI 0.10 to 0.30), low-density lipoprotein -0.10 (95% CI -0.13 to -0.07), total cholesterol -0.15 (95% CI -0.21 to -0.09), triglycerides -0.16 (95% CI -0.24 to -0.08), systolic blood pressure -0.20 (95% CI -0.23 to -0.17), diastolic blood pressure -0.20 (95% CI -0.22 to -0.18), fasting blood plasma glucose -0.10 (95% CI -0.12 to -0.08).

CONCLUSION

Ramadan fasting appears to benefit body weight, lipid profile, blood pressure, and fasting blood glucose levels. Therefore, engaging in fasting during Ramadan may contribute to weight reduction, decreased cardiovascular disease risk, improved blood pressure, and enhanced glycemic control. Nevertheless, the methodological quality of the included reviews ranged from low to critically low, necessitating cautious interpretation of conclusions drawn from these data.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework Identifier: DOI 10.17605/OSF.IO/9WVJZ.

The impact of Ramadan fasting on the metabolic syndrome severity in relation to ethnicity and sex: Results of a systematic review and meta-analysis

AIMS

The primary goal of this meta-analysis was to examine the changes in various components of metabolic syndrome (MetS) in healthy adults who observed Ramadan fasting (RF) before Ramadan (T1) and at the end of RF (T2). A secondary goal was to assess the impact of RF on MetS severity in various ethnic and sex groups using the MetS z-score.

DATA SYNTHESIS

Using PRISMA2020, seven databases were searched for relevant studies published between January 1950 and March 2022. Data extraction involved high-density lipoprotein cholesterol (HDL), triglycerides (TG), fasting blood glucose (FBG), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) for T1 and T2, respectively. The MetS z-score was computed according to international diabetes federation criteria. At T1, the pooled estimates of HDL, TG, FBG, WC, SBP, DBP, and MAP were 1.20 [1.13; 1.27] mmol/L, 1.32 [1.23; 1.42] mmol/L, 4.98 [4.82; 5.15] mmol/L, 87.21 [84.21; 90.21] Cm, 114.22 [101.45; 126.99] mmHg, 76.80 [70.12; 83.47] mmHg, and 89.27 [80.56; 97.98] mmHg, respectively. At T2, the pooled estimates of HDL, TG, FBG, WC, SBP, DBP, and MAP were 1.24 [1.18; 1.31] mmol/L, 1.24 [1.14; 1.34] mmol/L, 4.77 [4.55; 4.99] mmol/L, 85.73 [82.83; 88.64] Cm, 109.48 [97.20; 121.75] mmHg, 74.43 [68.01; 80.85] mmHg, and 86.11 [77.74; 94.48] mmHg, respectively. The MetS z-score showed improvement at T2 for all ethnic groups and both sexes by -0.22 [-0.24; -0.01].

CONCLUSIONS

The current meta-analysis suggests that the RF positively impact the MetS components and the overall MetS z-score.

PROSPERO REGISTRATION NUMBER

ID CRD42022329297 OPEN SCIENCE FRAMEWORK IDENTIFIER: DOI 10.17605/OSF.IO/U9H7T.