AGE-SPECIFIC REFERENCE VALUES OF NOCTURNAL SALIVARY MELATONIN IN THE POPULATION OF THE REPUBLIC OF UZBEKISTAN
Keywords:
melatonin, salivary melatonin, circadian rhythm, age-related changes, reference intervals, nocturnal secretion, Uzbekistan.Abstract
This study aimed to establish age-specific reference intervals for nocturnal salivary melatonin in apparently healthy individuals from the Republic of Uzbekistan. A total of 200 participants aged 6–69 years were divided into five age groups. Nocturnal salivary melatonin concentrations were measured by enzyme-linked immunosorbent assay under standardized low-light conditions. A pronounced age-related decline in melatonin secretion was observed, with mean concentrations decreasing from 150.60±5.64 pg/mL in children aged 6–12 years to 19.47±3.50 pg/mL in participants aged ≥60 years. Differences between age groups were statistically significant (F=192.7; p<0.001). Age-specific P5–P95 intervals were established for all five age categories. The findings demonstrate substantial age-related variability in nocturnal salivary melatonin concentrations and support the use of age-adapted reference intervals for clinical and research interpretation.
