Interestingly, we also observed a decline in the levels of IGF-1 with increasing number of helminth infections, which was more pronounced when infection was detected by PCR [mean difference (95% CI) − 0.044 (− 0.064; − 0.024), P < 0.001 after adjustment for age, sex, BMI, and fasting insulin level) compared to by microscopy [− 0.033 (− 0.053; − 0.013, P = 0.001] (see also Fig. 2a,b). This evidence concerns the gene INS and helminthiasis.