Relationships between micronutrient losses in sweat and blood pressure among heat-exposed steelworkers

Abstract

We aimed to examine the effect of micronutrient losses through sweat on blood pressure (BP) among heat-exposed steelworkers. A total of 224 heat-exposed male steelworkers from an ironworks facility were evaluated in July 2012. We measured the Wet Bulb Globe Temperature Index to evaluate the level of heat stress in the workplace. We collected sweat from the workers during an eight-hour work, and then we measured the micronutrients in the sweat. We also measured the BP of each worker. The results revealed that vitamin C, potassium, and calcium losses in sweat were positively correlated with systolic (SBP) and diastolic (DBP) blood pressure (all P<0.05). A linear stepwise regression analysis revealed that potassium, and calcium losses in sweat adversely affected SBP and DBP (all P<0.05). An analysis of covariance showed that SBP increased when potassium or calcium losses in sweat were >900 mg, or >100 mg, respectively. Further, DBP increased when potassium or calcium losses in sweat were >600 mg or >130 mg, respectively. Therefore, vitamin C, potassium, and calcium losses in sweat may adversely effect BP. To help steelworkers maintain healthy BP, facilities with high temperatures should try to lower environmental temperatures to reduce vitamin C, potassium, and calcium losses in sweat. Additionally, heat-exposed steelworkers may need to increase their dietary intakes of vitamin C, potassium, and calcium. Further research is needed to confirm these findings and support these recommendations.

Physiology of sweat gland function: The roles of sweating and sweat composition in human health

“…First, it is important to reiterate that many of the studies reporting substantial trace mineral and vitamin losses in sweat have used methods (e.g. arm bag or other regional techniques, scraping methods, minimal cleaning, inclusion of initial sweat at start of exercise) [226,[280][281][282][283][284] [134] recognized that a primary source of Ca and Fe found in sweat is associated with desquamated cell debris, which is characteristic of the arm bag technique. Regional measures of sweat trace minerals are also higher and more variable (e.g.…”

Physiological mechanisms determining eccrine sweat composition

“…With regard to vitamin secretion in sweat, ascorbic acid and thiamine are large polar molecules (Table 1) and, therefore, may be secreted through a paracellular route albeit exact mechanisms are unknown. Few studies have measured water-soluble vitamin concentrations in sweat (Mickelsen and Keys 1943;Thapar et al 1976) and in some cases interpretation is difficult due to limited methodologies (scraping) used (Tang et al 2016). The authors are unaware of any studies reporting sweat concentrations of fat-soluble vitamins.…”

Electrochemical detection of ascorbic acid in artificial sweat using a flexible alginate/CuO-modified electrode

“…The use of simple gold electrodes on polyimide makes it compatible with a variety of techniques like inkjet printing or photolithography and with the future application as a flexible, wearable device. Finally, the determination of ascorbic acid is done at the micromolar range as it is found in sweat [3,46], and in artificial perspiration solution without interference of any of the other present biomolecules.…”

“…The long-time known essential ascorbic acid (vitamin C) is a water-soluble molecule that, like other water-soluble vitamins, cannot be stored in the body for a long time [ 1 ]; it can be found in secreted body fluids, e.g., sweat [ 2 ]. Consequently, heat-exposed activities (e.g., in steel factories) or prolonged sport sessions result in nutrient loss through sweating, including that of ascorbic acid [ 3 ], making it necessary to monitor them for the on-time response by dietary intake without delay. Thus, ascorbic acid is an important target for quantitative sensing and monitoring in the biomedical field, relevant also for the food and beverage industry, e.g., for quality control.…”