Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, Michigan, USA.
Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland.
Prostate. 2021 Jun;81(8):487-496. doi: 10.1002/pros.24130. Epub 2021 Apr 16.
Melatonin levels are partially driven by the parenchyma volume of the pineal gland. Low urinary levels of 6-sulfatoxymelatonin have been associated with increased risk of advanced prostate cancer, but the relationship between pineal gland volume and composition and prostate cancer risk has not been examined.
We utilized data from 864 men from the AGES-Reykjavik Study with complete pineal gland volumes and urinary 6-sulfatoxymelatonin measurements. Pineal parenchyma, calcification, and cyst volumes were calculated from brain magnetic resonance imaging. Levels of 6-sulfatoxymelatonin were assayed from prediagnostic urine samples. We calculated Pearson correlation coefficients between parenchyma volume and urinary 6-sulfatoxymelatonin levels. We used Cox proportional hazards regression to calculate multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) comparing prostate cancer risk across parenchyma volume tertiles and across categories factoring in parenchyma volume, gland composition, and urinary 6-sulfatoxymelatonin level.
Parenchyma volume was moderately correlated with urinary 6-sulfatoxymelatonin level (r = .24; p < .01). There was no statistically significant association between parenchyma volume tertile and prostate cancer risk. Men with high parenchyma volume, pineal cysts and calcifications, and low urinary 6-sulfatoxymelatonin levels had almost twice the risk of total prostate cancer as men with low parenchyma volume, no pineal calcifications or cysts, and low urinary 6-sulfatoxymelatonin levels (HR: 1.98; 95% CI: 1.02, 3.84; p: .04).
Although parenchyma volume is not associated with prostate cancer risk, pineal gland composition and other circadian dynamics may influence risk for prostate cancer. Additional studies are needed to examine the interplay of pineal gland volume, composition, and melatonin levels on prostate cancer risk.
褪黑素水平部分受松果体实质体积的驱动。尿中 6-硫酸褪黑素水平较低与前列腺癌进展风险增加有关，但松果体体积和组成与前列腺癌风险之间的关系尚未被研究。
我们利用了来自 AGES-雷克雅未克研究的 864 名男性的数据，这些男性的松果体体积完整，尿液中 6-硫酸褪黑素的测量结果完整。松果体实质、钙化和囊肿体积是从脑磁共振成像中计算出来的。6-硫酸褪黑素的水平是从预测前的尿液样本中检测出来的。我们计算了实质体积和尿中 6-硫酸褪黑素水平之间的皮尔逊相关系数。我们使用 Cox 比例风险回归来计算多变量风险比（HRs）和 95%置信区间（95%CI），比较了松果体实质体积三分位组和松果体实质体积、腺体组成和尿 6-硫酸褪黑素水平分类下的前列腺癌风险。
实质体积与尿中 6-硫酸褪黑素水平中度相关（r=0.24；p<0.01）。松果体实质体积三分位组与前列腺癌风险之间没有统计学上的显著关联。松果体实质体积高、松果体囊肿和钙化、尿中 6-硫酸褪黑素水平低的男性患总前列腺癌的风险几乎是松果体实质体积低、无松果体钙化或囊肿、尿中 6-硫酸褪黑素水平低的男性的两倍（HR：1.98；95%CI：1.02，3.84；p：0.04）。
尽管实质体积与前列腺癌风险无关，但松果体腺体组成和其他昼夜节律动态可能影响前列腺癌的风险。需要进一步的研究来检查松果体体积、组成和褪黑素水平对前列腺癌风险的相互作用。
