Oh J K, Kim K T, Yoon S J, Kim S W, Kim T B
Department of Urology, Gachon University Gil Hospital, Incheon, Korea.
Andrology. 2014 Nov;2(6):862-7. doi: 10.1111/j.2047-2927.2014.00256.x. Epub 2014 Aug 12.
It has been suggested that second to fourth digit ratio (digit ratio) may correlate with male reproductive system function or disorders. This hypothesis is based on finding that the Hox genes control finger development and differentiation of the genital bud during embryogenesis. Thus, we investigated the association between digit ratio and adult testicular volume. A total of 172 Korean men (aged 20-69 years) hospitalized for urological surgery were prospectively enrolled. Patients with conditions known to strongly influence testicular volume were excluded. Before determining testicular volume, the lengths of the second and fourth digits of the right hand were measured by a single investigator using a digital vernier calliper. Using orchidometry, the testes were measured by an experienced urologist who had no information about the patient's digit ratio. To identify the independent predictive factors influencing testicular volume, univariate and multivariate analyses were performed using linear regression models. Age, height, serum testosterone and free testosterone level were not correlated with testicular volume. Digit ratio, along with weight, was significantly correlated with testicular volume (right testicular volume: r = -0.185, p = 0.015; left testicular volume: r = -0.193, p = 0.011; total testicular volume: r = -0.198, p = 0.009). Multivariate analysis using linear regression models showed that only digit ratio was the independent factor to predict all (right, left and total) testicular volumes (right testicular volume: β = -0.174, p = 0.023; left testicular volume: β = -0.181, p = 0.017; total testicular volume: β = -0.185, p = 0.014). Our findings demonstrated that digit ratio is negatively associated with adult testicular volume. This means that men with a higher digit ratio may be more likely to have smaller testis compared to those with a lower digit ratio.
有人提出，食指与无名指比例（指比）可能与男性生殖系统功能或疾病相关。这一假说基于以下发现：Hox基因在胚胎发育过程中控制手指发育和生殖芽的分化。因此，我们研究了指比与成年男性睾丸体积之间的关联。前瞻性纳入了172名因泌尿外科手术住院的韩国男性（年龄在20 - 69岁之间）。排除已知会强烈影响睾丸体积的疾病患者。在确定睾丸体积之前，由一名研究人员使用数字游标卡尺测量右手食指和无名指的长度。使用睾丸体积测量法，由一位对患者指比情况不知情的经验丰富的泌尿外科医生测量睾丸。为了确定影响睾丸体积的独立预测因素，使用线性回归模型进行单因素和多因素分析。年龄、身高、血清睾酮和游离睾酮水平与睾丸体积均无相关性。指比与体重一起，与睾丸体积显著相关（右侧睾丸体积：r = -0.185, p = 0.015；左侧睾丸体积：r = -0.193, p = 0.011；总睾丸体积：r = -0.198, p = 0.009）。使用线性回归模型的多因素分析表明，只有指比是预测所有（右侧、左侧和总）睾丸体积的独立因素（右侧睾丸体积：β = -0.174, p = 0.023；左侧睾丸体积：β = -0.181, p = 0.017；总睾丸体积：β = -0.185, p = 0.014）。我们的研究结果表明，指比与成年男性睾丸体积呈负相关。这意味着与指比低的男性相比，指比高的男性睾丸可能更小。
