Limitations
Finally, it is important to mention the limitations of the present study. First of all, due to the lack of randomized clinical trials in literature, we based our review and meta-analysis on only cohort and case-control studies with a full-text available in English. This way, articles with content relevant to our study but written in another language may have been omitted. Secondly, the number of studies as well as the population examined was limited and the majority came from only two countries, Turkey and Finland. Thirdly, all included studies had variations concerning the baseline characteristics of the study population (sex, BMI, age, comorbidities) and methodology (dosage, duration of treatment). Such variations may have affected adiponectin and insulin resistance levels and were confusing factors that could not be weighed out. Nevertheless, according to the I2 test the heterogeneity was low.
It seems that there is not a great interest regarding the effect of isotretinoin on insulin resistance. This is evident by the small number of published studies, as well as from the fact that, even there are a few registered RCTs regarding the safety and efficacy of isotretinoin, none of them assesses the possible role of isotretinoin in insulin resistance.