Sex-specific effects of calving season on joint health and biomarkers in Montana ranchers

• Published in: BMC musculoskeletal disorders Vol. 24; no. 1; p. 80
• Main Authors: Thompson, Matthew A, Martin, Stephen A, Hislop, Brady D, Younkin, Roubie, Andrews, Tara M, Miller, Kaleena, June, Ronald K, Adams, Erik S
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 31.01.2023; BioMed Central; BMC
• Subjects: Agriculture; Analysis; Arthralgia; Arthritis; Biological markers; Biomarkers; Cartilage; Cluster analysis; Collagen; Diagnosis; Etiology; Farmers; Farmworkers; Female; Health aspects; Humans; Hyaluronic acid; Inflammation; Interleukin 2; Interleukin 6; Joint pain; Leptin; Male; Matrix metalloproteinase; Metalloproteinase; Montana; Musculoskeletal diseases; Osteoarthritis; Osteoarthritis, Knee - diagnosis; Osteoarthritis, Knee - epidemiology; Oxidative stress; Pain; Ranching; Risk factors; Saliva; Seasons; Self report; Sex differences; Sexual dimorphism; Statistical analysis; Stromelysin 1; Surveys; Thiobarbituric acid; Urine; Variance analysis; Womens health; Montana; United States > US; Joint pain; Calving season; Biomarkers; Sex differences; Inflammation; Ranching; Osteoarthritis
• ISSN: 1471-2474; 1471-2474
• DOI: 10.1186/s12891-022-05979-2

Agricultural workers have a higher incidence of osteoarthritis (OA), but the etiology behind this phenomenon is unclear. Calving season, which occurs in mid- to late-winter for ranchers, includes physical conditions that may elevate OA risk. Our primary aim was to determine whether OA biomarkers are elevated at the peak of calving season compared to pre-season, and to compare these data with joint health survey information from the subjects. Our secondary aim was to detect biomarker differences between male and female ranchers. During collection periods before and during calving season, male (n = 28) and female (n = 10) ranchers completed joint health surveys and provided samples of blood, urine, and saliva for biomarker analysis. Statistical analyses examined associations between mean biomarker levels and survey predictors. Ensemble cluster analysis identified groups having unique biomarker profiles. The number of calvings performed by each rancher positively correlated with plasma IL-6, serum hyaluronic acid (HA) and urinary CTX-I. Thiobarbituric acid reactive substances (TBARS), a marker of oxidative stress, was significantly higher during calving season than pre-season and was also correlated with ranchers having more months per year of joint pain. We found evidence of sexual dimorphism in the biomarkers among the ranchers, with leptin being elevated and matrix metalloproteinase-3 diminished in female ranchers. The opposite was detected in males. WOMAC score was positively associated with multiple biomarkers: IL-6, IL-2, HA, leptin, C2C, asymmetric dimethylarginine, and CTX-I. These biomarkers represent enzymatic degradation, inflammation, products of joint destruction, and OA severity. The positive association between number of calvings performed by each rancher (workload) and both inflammatory and joint tissue catabolism biomarkers establishes that calving season is a risk factor for OA in Montana ranchers. Consistent with the literature, we found important sex differences in OA biomarkers, with female ranchers showing elevated leptin, whereas males showed elevated MMP-3.