Prolonged and intensive medication use are associated with the obesity paradox after percutaneous coronary intervention: a systematic review and meta-analysis of 12 studies.

backgroundObesity paradox is defined as the unexpected decrease in the total number of death which has been observed among patients who are overweight and obese compared to patients with normal weight after undergoing revascularization by percutaneous coronary intervention (PCI). Despite of so many recent studies which showed the existence of this phenomenon, prolonged and intensive medication use were only suggested to be among the reasons responsible for this 'obesity paradox' but it was never confirmed whether this hypothesis should really be considered true or not. Therefore, this study aimed to investigate whether prolonged and intensive medication use were associated with this obesity paradox after PCI.

methodsMedline, PubMed, EMBASE and the Cochrane Library were searched for studies showing the existence of this 'obesity paradox' in patients who underwent coronary revascularization by PCI and only articles comprising of medication use among the patients analyzed were considered relevant for this research. Medication use among the different subgroups of patients was calculated. Mortality was considered as the clinical endpoint in this study. Risk Ratio (RR) with 95 % Confidence Interval (CI) was used to express the pooled effect on discontinuous variables and the pooled analyses were performed with RevMan 5.3.

resultsTwelve studies consisting of a total number of 91,582 patients was included in this meta-analysis. An intensive medication use after the hospital discharge and during the follow up period after PCI was observed in the subgroup of obese patients, followed by the overweight patients and the normal weight patients respectively. Our results showed that the short-term (30 days) mortality in overweight and obese patients was significantly lower compared to the normal weight patients with RR: 0.72; 95 % CI: 0.56-0.92, p = 0.008 and RR: 0.47, 95 % CI: 0.34-0.65; p < 0.00001 respectively. The long-term (≥ one year) mortality was also significantly lower in the overweight and the obese groups with RR: 0.74, 95 % CI: 0.67-0.82; p < 0.00001 and RR: 0.63, 95 % CI: 0.55-0.72; p < 0.00001 respectively.

conclusionOur study has confirmed to some extent, that prolonged and intensive use of medications which were more prominent in patients who were overweight and obese during the follow up period, might apparently be among the reasons responsible for this obesity paradox after PCI.