Using sweat to measure cytokines in older adults compared to younger adults: A pilot study

Background/objectives: Current measures of cytokines involve urine, blood or saliva which have drawbacks including circadian rhythm variations and complicated collection methods. Sweat has been used to measure cytokines in young and middle-aged adults, but not older adults. We sought to determine the feasibility of using sweat to measure cytokines in older adults compared to younger adults. Design: Two visit cross-sectional pilot study stratified by age group. Setting: Independent living facility and Johns Hopkins University both in Maryland. Participants: 23 community-dwelling adults aged 65 and older and 26 adults aged 18-40 were included. Those with active cancer treatment or with a known terminal illness diagnosis were excluded. Measurements: Sweat interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-α) were collected using a non-invasive sweat patch worn for 72. h by each participant. Samples were measured with a single molecule array (SIMOA) technology for ultrasensitive, multiplexed detection of proteins. Results: 23 older adults and 26 younger adults with mean ages of 77. ±. 8.0. years and 28. ±. 5.5. years, respectively, completed the study. Both groups had high rates of compliance with patch wearing and removal. Higher concentrations of TNF-α, IL-6 and IL-10 were observed in older adults compared to younger adults, which remained significant after controlling for race, sex, body mass index, and chronic disease count (0.110. ±. 0.030 vs. 0.054. ±. 0.020. pg/mL, 0.089. ±. 0.012 vs. 0.048. ±. 0.018. pg/mL, and 0.124. ±. 0.029 vs. 0.067. ±. 0.025. pg/mL, respectively). Conclusion: These results suggest that sweat patches are a feasible method to collect cytokine data from older adults. Preliminary group differences in cytokine measurement between older and younger groups correspond with current literature that cytokines increase with age, suggesting that sweat measurement using the sweat patch provides a new method of exploring the impact of inflammation on aging. Further research using sweat and the sweat patch is recommended.