Bivariate correlations for all key variables.

Religiosity and spirituality (R/S) are central aspects to the lives of many people worldwide. Previous research suggests a potentially beneficial relationship between R/S, mostly understood as religious service attendance, and mortality. Though important, this research often fails to account for the complex and multidimensional nature of R/S. Also lacking is an adequate understanding of the physiological mechanisms that may link R/S with mortality and other health outcomes. Insulin resistance and metabolic syndrome, subclinical physiological processes that are influenced by the types of lifestyle factors and psychological factors that R/S addresses, serve as two possible biological mechanisms linking R/S and health outcomes. This study investigated the relations of R/S, defined as service attendance, support from one’s religious community, and composite variables comprised of several diverse R/S indicators, in relation to insulin resistance and metabolic syndrome both cross-sectionally and in longitudinal analyses across 8–10 years in the Midlife in the United States (MIDUS) study. Results, controlling for important covariates (demographic factors, self-rated health, chronic conditions, depressive symptoms for all analyses; diabetes status and body mass index for insulin resistance analyses; antihyperlipidemic medications for metabolic syndrome), demonstrated nonsignificant relationships for all measures of R/S and both insulin resistance and metabolic syndrome in both cross-sectional and longitudinal analyses. Integrating these findings into the limited research on physiological mechanisms in the R/S and health relationship suggests that the area lacks consistent findings. Additional studies that use heterogenous, representative samples and further refine the operationalization of R/S are indicated.