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Testosterone and FSH are interconnected hormones in male reproductive health, co-analyzed in studies on seasonal variations using measurements and statistical tests [1], [2], [3], [4], with shared reference ranges [5] and consistent findings across referenced studies [6], [7], [8]. They are jointly assessed in blood tests for hormonal health [9] and linked in conditions like Klinefelter syndrome with elevated FSH and altered testosterone ratios [10], as well as secondary hypogonadism where FSH deficiency causes low testosterone [11].
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Seasonal Changes of Serum Gonadotropins and Testosterone in ... frontiersin.org 8 facts
referenceNicolau et al. (1985) investigated circadian and circannual variations of FSH, LH, testosterone, DHEA-S, and 17-hydroxy progesterone in elderly men and women.
measurementThe laboratory reference ranges used in the study were 2.2–8.7 ng/dL for testosterone, 1–9 IU/L for LH, 1–12 IU/L for FSH, and 3–13 ng/mL for PRL.
procedureTo evaluate the role of age on sexual hormone variations, the researchers divided the entire cohort into quartiles based on age distribution and evaluated testosterone, LH, and FSH distribution among seasons within each quartile.
procedureThe study 'Seasonal Changes of Serum Gonadotropins and Testosterone in...' analyzed testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) measurements collected between January 2010 and January 2019 using Chemiluminescent Microparticle Immunoassay, excluding subjects with factors interfering with the hypothalamic-pituitary-gonadal axis.
procedureTo evaluate the role of the environment on sexual hormones, the researchers performed bivariate correlations between testosterone, LH, and FSH and environmental factors including maximum, minimum, and mean temperatures, humidity, and daylight duration using Rho's Spearman correlation.
procedureThe researchers compared the mean values of testosterone, LH, and FSH among seasons using the Kruskal-Wallis test, followed by post hoc analyses using the Tukey test.
measurementMartikainen et al. (34) studied 22 young men in Finland and detected no seasonality for testosterone, LH, or FSH.
measurementMeriggiola et al. (35) studied 16 healthy men in Italy and found annual peaks for testosterone, LH, and FSH in summer.
Understanding Male Hormonal Changes: A Complete Guide (2025) coremedicalwellness.com 1 fact
claimBlood tests for male hormonal health typically measure total and free testosterone, thyroid hormones (TSH, T3, and T4), and other hormones such as LH, FSH, prolactin, DHEA, and cortisol.
Bridging the Gap Between LLMs and Evolving Medical Knowledge arxiv.org 1 fact
claimKlinefelter syndrome is associated with paternal nondisjunction, which involves an error in meiosis I during spermatogenesis, and presents clinically with tall stature, long limbs, sparse body hair, gynecomastia, small testes, elevated FSH, and a high estradiol:testosterone ratio.
Physiology, Male Reproductive System - StatPearls - NCBI Bookshelf ncbi.nlm.nih.gov 1 fact
claimIn cases of secondary hypogonadism, Leydig and Sertoli cells remain functional and intact but cannot exert their effects due to a lack of proper stimuli (GnRH, LH, or FSH), resulting in low testosterone levels or loss of spermatogenesis.