Objectives Policing is considered a high-stress occupation and officers have elevated cardiovascular morbidity and mortality. We evaluated the association between salivary cortisol response to a standardised challenge and the metabolic syndrome (MetSyn), an indicator of increased cardiovascular risk.

Method Cross-sectional data from the Buffalo Cardio-Metabolic Occupational Police Stress Study (2004–2009) were analysed. MetSyn was defined as three or more of five components: abdominal obesity, hypertension, elevated triglycerides, reduced high-density lipoprotein cholesterol, and glucose intolerance. Officers provided five salivary cortisol samples, one before challenge (ingestion of a high-protein shake) and four at 15-minute intervals thereafter, where increase represents normal response. Age- and sex-adjusted regression models were used to examine trends in mean number of components across quartiles of area under the curve (AUC) salivary cortisol. Patterns of mean cortisol response were assessed by MetSyn status using repeated-measures analysis of covariance.

Results The study included 373 officers (74.0% men) with a mean age of 41.0 years. Prevalence of MetSyn was 25.7%. The mean count of MetSyn components decreased (1.89, 1.75, 1.55, 1.37; P < 0.01) across increasing quartiles of AUC salivary cortisol. The pattern of mean salivary cortisol decreased from baseline (5.55, 4.58, 4.47, 4.79, 4.75 nmol/L) in officers with MetSyn and increased (5.08, 5.82, 5.92, 5.82, 5.60 nmol/L) in their counterparts. The test for interaction between MetSyn status and sample timing was statistically significant (P < 0.001).

Conclusions A reduced cortisol response to a high-protein challenge may be associated with MetSyn. Future longitudinal studies could provide useful evidence for planning intervention studies on cardiovascular risk among police officers.