The Pooled Cut-off Point of Waist Circumference as CoreComponent of Metabolic Syndrome Diagnosis amongthe Iranian Population: a Systematic Review and Meta-analysis

According to a nationwide study, one-third of the Iranian population suffer from metabolic syn-drome (MetS). The most controversial criteria for the diagnosis of MetS is central obesity which would be definedby waist circumference (WC) and needed to be gender and ethnic-specific. There are several national studiesthat reported different cut-offs for WC so the present study aimed to do a systematic review and meta-analysisto achieve an overall statistical estimate of WC for the Iranian population.

A comprehensive searchwas conducted in international databases from inception to June 2020. The search keywords were waist circum-ference AND metabolic syndrome AND cut AND Iran. We used the QUADAS-2 tool for quality assessment andthe HSROC model for estimating pooled specificity, sensitivity, and the cut-off point from included studies in Rsoftware.

A total of 3571 studies were evaluated and 24 studies fulfilled the inclusion criteria. Finally,8 studies were included. All the studies were cross-sectional. Studies with missing MetS prevalence were ex-cluded. Most of the studies had an unclear risk of bias in patient selection. There was a wide variation amongreported cut-offs for WC from national and original studies. The Pooled cut-off points of WC for the diagnosisof MetS was 90.55 cm (95%CI: 90.51-90.60) in men and 89.24 cm (95%CI: 89.13-89.36) in women. The pooledsensitivity and specificity in men were 0.67 and 0.68, respectively and the pooled sensitivity and specificity inwomen were 0.61 and 0.57, respectively.

Our results were highly consistent with the only nationalstudy and the only consensus about WC cut-off. Further nationwide studies are suggested to be involved in aMata-analysis for calculating more precise WC cut-off.