Causes of variation in the neutrophil-lymphocyte and platelet-lymphocyte ratios: a twin-family study.

AIM: Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are biomarkers for disease development, for whom little is known about causes of variation in the general population. MATERIALS & METHODS: We estimated the heritability of PLR and NLR and examined their association with gender, demographic, lifestyle and environmental factors in a Dutch nonpatient twin family population (n = 8108). RESULTS: Heritability was estimated at 64% for PLR and 36% for NLR. Men had on average higher NLR, but lower PLR levels than women. PLR and NLR increased significantly with age, decreased in colder months and showed small but significant sex- and age-specific associations with body composition and smoking. CONCLUSION: NLR and PLR levels are heritable and influenced by age, sex and environmental factors, such as seasonal conditions and lifestyle.