Associations of individual and mixtures of organophosphate pesticides with the risk of osteoporosis in adult population†

The impact of organophosphate pesticide (OPP) exposure on osteoporosis in adult population remains unclear. Thus, it is necessary to explore the association between the exposure to a mixture of OPPs and the prevalence of osteoporosis as well as to identify the major contributor of OPPs in this association. Participants were selected from the 2005–2008 cycle of the NHANES cross-sectional study. OPP exposure was estimated using six different metabolites found in urine. Dual-energy X-ray absorptiometry (DXA) was used to measure bone mineral density (BMD). Survey-weighted generalized linear regression models (SWGLMs) were used to estimate the association between individual OPP exposure and osteoporosis/BMD. Weighted quantile sum (WQS) regression and quantile g-computation (Qgcomp) models were used to assess the mixture of OPPs and identify the key pollutants. SWGLMs indicated that higher concentrations of dimethyl dithiophosphate (DMDTP) and diethyl dithiophosphate (DEDTP) were associated with increased osteoporosis risk in the upper quartiles. WQS models revealed a significant combined effect of six OPP metabolites on osteoporosis (OR = 1.35, 95% CI: 1.06–1.73, P = 0.015), femoral neck BMD (β = −0.012, 95% CI: −0.020, −0.004, P = 0.003) and lumbar spine BMD (β = −0.015, 95% CI: −0.025, −0.006, P = 0.001), with DMDTP and DEDTP identified as key pollutants. Results from the Qgcomp models showed no substantial changes. This study indicated that exposure to both individual OPPs and their mixtures were associated with decreased BMD and increased osteoporosis risk, with DMDTP and DEDTP identified as major contributors to these associations. This underscores the need to prioritize control of these two pollutants to limit their exposure for osteoporosis prevention.