George Adekunle Olufemi, Shittu Olayiwola Babatunde, Enwerem Eokezie, Wachtel Mitchell, Kuti Olufemi
Dermatology Unit, Department of Medicine, University College Hospital, Ibadan, Nigeria.
J Natl Med Assoc. 2005 May;97(5):685-8.
The incidence of linea nigra was studied in 1,550 Nigerians of both sexes and of different age groups and among pregnant women and men with benign and malignant prostatic diseases over a nine-month period. From the study, it would appear that linea nigra increases in incidence from the age group 0-15 years (31.4%) to the age group 16-30 years (47.3%) before starting to fall in clinically normal individuals >30 years to 19.2%. For age groups 0-5 years, 6-10 years and 16-30 years, females more often than males have a linea nigra. For age group 11-15, males are equally as likely as females to have a linea nigra. The results suggest that women over 30 are more likely to have a linea nigra than men, but there are too few patients to make a definite statement, given the number of statistical tests performed. Pregnant women far more often have a linea nigra than nonpregnant women of the same age. The findings suggest that the likelihood of having a linea nigra depends on the level of sex hormones. This means that changes in the levels of hormones, either due to disease or drugs, may be reflected in changes in the incidence of a linea nigra. If this finding is confirmed, the linea nigra may serve as a convenient, noninvasive, free marker of alterations in sex hormones.
在九个月的时间里，对1550名不同年龄组的尼日利亚男女、孕妇以及患有良性和恶性前列腺疾病的男性进行了研究，以探讨黑线的发生率。从研究中可以看出，黑线的发生率在0至15岁年龄组（31.4%）到16至30岁年龄组（47.3%）呈上升趋势，之后在30岁以上的临床正常个体中开始下降至19.2%。在0至5岁、6至10岁以及16至30岁年龄组中，女性出现黑线的情况比男性更为常见。在11至15岁年龄组中，男性和女性出现黑线的可能性相同。结果表明，30岁以上的女性比男性更有可能出现黑线，但鉴于所进行的统计测试数量，患者数量过少，无法做出明确的陈述。孕妇出现黑线的情况远比同年龄的非孕妇更为常见。研究结果表明，出现黑线的可能性取决于性激素水平。这意味着，无论是由于疾病还是药物导致的激素水平变化，都可能反映在黑线发生率的变化上。如果这一发现得到证实，黑线可能成为一种方便、无创、免费的性激素变化标志物。
