The effect of noise on serum and urinary magnesium and catecholamines in humans.
Level 4 - case-series / case-control
Uncontrolled pre-post study in 25 volunteers without a separate non-exposed control group.
PubMed 11235829 · doi:10.1093/occmed/51.1.56
What was done
Twenty-five healthy volunteers were exposed to loud industrial noise with an average sound level of 98 dB(A) and peaks up to 108 dB(A). Blood and urine samples were collected at baseline (08:00 h) and immediately after exposure (20:00 h), followed by morning urine collections 1 and 2 days post-experiment (08:00 h). Serum and urinary levels of magnesium, calcium, phosphorus/phosphate, and creatinine were measured, along with urinary catecholamines (adrenaline, noradrenaline, and dopamine) via high-performance liquid chromatography.
What was found
Serum magnesium and calcium significantly increased after noise exposure (MANOVA after exposure P < 0.001), while serum phosphorus showed a non-significant trend (P = 0.065). Urinary magnesium excretion significantly differed over time (P = 0.017), and urinary phosphate increased significantly (P = 0.007), lasting for the subsequent 2 days. Urinary calcium (P = 0.36) and urinary creatinine (P > 0.05) did not change significantly. Urinary adrenaline, noradrenaline, and dopamine did not show statistically significant differences (P > 0.05). No absolute numerical concentrations, baseline figures, or effect sizes were reported in the abstract.
Why it matters
The findings suggest that acute acoustic stress can alter electrolyte homeostasis—specifically triggering prolonged urinary excretion of magnesium and phosphate—independent of detectable changes in urinary catecholamine levels.
Limits
The study was small (n = 25) and lacked an unexposed control group, confounding the findings with diurnal variation (08:00 h vs. 20:00 h) and dietary intake. The abstract provides no absolute numerical values, standard deviations, or effect sizes.
Cited by
- contradicts Noise exposure stress decreases magnesium levels in humans and causes urinary magnesium excretion to peak within a few hours and remain elevated for up to two days.