Low serum melatonin levels are associated with erectile dysfunction

ABSTRACT Objective: Melatonin is a hormone secreted from the pineal gland and has anti-oxidative and anti-inflammatory effects. Oxidative stress is considered as an important factor in the etiology of erectile dysfunction (ED), and in many experimental models, positive results have been obtained with melatonin treatment. This study aimed to measure serum melatonin levels in ED patients and to investigate the possible relationship between ED and melatonin levels. Materials and Methods: Sixty-two patients diagnosed with mild, moderate or severe ED according to the five-item International Erectile Function Index (IIEF-5) and 22 healthy individuals were included in the study. The serum melatonin levels, anthropometric data, and other biochemical and hormonal parameters of all the subjects were recorded. Detailed anamnesis was also obtained in terms of diabetes, hypertension, cardiovascular diseases, smoking status, and alcohol use. Results: The serum melatonin level was found 34.2±13.3 ng/dL in the mild ED group, 33.3±14.7 ng/dL in the moderate ED group, 34.8±17.2 ng/dL in the severe ED group, and 44.6±16.5 ng/dL in the control group. The serum melatonin levels were significantly lower in all ED groups compared to the control group (p=0.019). There was no significant difference in the serum melatonin levels between the three ED groups. Diabetes, hypertension, cardiovascular diseases, smoking and alcohol use were not significantly different between the ED groups (p>0.05). Conclusion: We consider that if our findings are supported by further studies with larger populations, the measurement of the serum melatonin level may have a future role in the diagnosis and treatment of ED.

摘要
研究目的：褪黑素（Melatonin）是由松果体分泌的激素，具备抗氧化与抗炎活性。氧化应激（Oxidative stress）被认为是勃起功能障碍（erectile dysfunction, ED）病因学中的关键影响因素，且在多项实验模型中，褪黑素干预均取得了积极效果。本研究旨在检测勃起功能障碍患者的血清褪黑素水平，并探讨ED与褪黑素水平之间的潜在关联。
材料与方法：本研究纳入62名依据国际勃起功能指数5项版（five-item International Erectile Function Index, IIEF-5）确诊为轻度、中度或重度ED的患者，以及22名健康个体。记录所有受试者的血清褪黑素水平、人体测量学数据，以及其他生化与激素参数；同时详细采集受试者的糖尿病、高血压、心血管疾病病史、吸烟史与饮酒史等临床信息。
结果：轻度ED组患者的血清褪黑素水平为34.2±13.3 ng/dL，中度ED组为33.3±14.7 ng/dL，重度ED组为34.8±17.2 ng/dL，对照组为44.6±16.5 ng/dL。相较于对照组，所有ED亚组的血清褪黑素水平均显著降低（p=0.019）；三个ED亚组之间的血清褪黑素水平无显著差异。ED各组间的糖尿病、高血压、心血管疾病患病率、吸烟率与饮酒率均无显著差异（p>0.05）。
结论：我们认为，若本研究结果在更大样本量的后续研究中得到验证，血清褪黑素水平检测有望在ED的诊断与治疗中发挥潜在应用价值。