High BMI protects against risk of lung cancer mortality
There is a nonlinear association between body mass index (BMI) and risk of lung cancer mortality, where individuals with higher BMI have less risk of death, according to a recent meta-analysis.
Among the 15 studies (n=15,191,571) eligible for inclusion, 28,273 deaths from lung cancer were reported. For every 5 kg/m2 increase in BMI, a pooled relative risk (RR) of 0.94 (95 percent CI, 0.92 to 0.96; p=0.000) for lung cancer mortality risk was calculated.
There was a significant nonlinear association between the risk of death from lung cancer and BMI (p<0.0001 for nonlinearity), such that those with lower BMI had higher risks of mortality from lung cancer.
Because of considerable heterogeneity, subgroup analyses were performed and showed that females benefited from high BMI more than males, as did smokers than nonsmokers.
The current meta-analysis involved studies that focused on the effect of BMI on the risk of mortality from lung cancer. The databases of Pubmed and Embase were accessed.
Of the 15 studies eligible, five were conducted in Europe, six in America and four in Asia. Sample size varied and ranged from 2,054 to 1,200,000 patients. All but one report were population-based studies. The total study duration lasted for more than 200 million person-years.
In terms of quality, seven of the 15 studies had high quality, according to the Newcastle-Ottawa scale. The remaining eight studies had moderate quality. The Egger and Begg tests showed that there was no evidence of publication bias.