BMC Endocr Disord：泌乳素与2型糖尿病患病率呈负相关

以往观察血清泌乳素浓度（PRL）与代谢综合征（MetS）和2型糖尿病（T2DM）的关系的研究都是在小型的、选择性研究样本，为了在大型基于人群的队列中，探讨血清泌乳素浓度与代谢综合征和2型糖尿病的潜在关系，来自德国格赖夫斯瓦尔德大学医学院的Robin Haring教授及其团队进行了一项研究，该研究发现在两种性别中，泌乳素都与2型糖尿病的流行之间呈横断面负相关。该研究结果发表在2013年5月的《英国医学会内分泌疾病》（BMC endocrine disorders）杂志上。

该研究的数据来自波美拉尼亚基于人口的健康调查研究，包括3993例（女性2027例）年龄20–79岁的受试者，在年龄和多变量校正Poisson回归模型中分析泌乳素与代谢综合征和2型糖尿病风险的横断面和纵向关系。泌乳素进行对数转换，并建模为连续型变量（每个标准差（SD）连续增加）和分类预测型变量（性别特异性四分位数），男性与女性分别计算。

该研究结果表明，横断面分析显示，多变量校正后，男性和女性的血清中低泌乳素浓度与2型糖尿病流行危险之间呈负相关(男性： Q1 vs Q4：相对风险(RR)，1.55；95%可信区间(CI)，1.13 –2.14；女性： Q1 vs Q4：RR，1.70；95%CI，1.10 –2.62)。同样，血清中较高的泌乳素浓度与2型糖尿病风险显著降低相关（泌乳素对数每增加一个标准差，RR分别为：男性0.83；95%CI，0.72–0.95；女性0.84；95%CI，0.71–0.98）。多变量校正后，泌乳素浓度与代谢综合征风险不存在负相关。纵向分析时，泌乳素与代谢综合征或2型糖尿病发生之间没有相关性。

该研究是第一个大样本基于人群的研究，发现在两种性别中，泌乳素都与2型糖尿病的流行之间呈横断面负相关。但因缺少纵向相关性，不支持泌乳素在代谢综合征或2型糖尿病发生中作为一个危险因素的因果作用。

Serum prolactin concentrations as risk factor of metabolic syndrome or type 2 diabetes?
BACKGROUND
To investigate potential associations of serum prolactin concentration (PRL) with metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM), previously observed in small and selected study samples, in a large population-based cohort.
METHODS
Data from 3,993 individuals (2,027 women) aged 20-79 years from the population-based Study of Health of Pomerania (SHIP) were used to analyse cross-sectional and longitudinal associations of PRL with MetS and T2DM risk in age- and multivariable-adjusted Poisson regression models. PRL were log-transformed and modelled as continuous (per standard deviation (SD) increase) and categorical predictor (sex-specific quartiles) variable, separately for men and woman.
RESULTS
Cross-sectional analyses showed an inverse association between low PRL concentrations and prevalent T2DM risk in men and women after multivariable-adjustment (men: Q1 vs. Q4: relative risk (RR), 1.55; 95% confidence interval (CI), 1.13 - 2.14; women: Q1 vs. Q4: RR, 1.70; 95% CI, 1.10 - 2.62). Likewise, higher PRL concentrations were associated with significantly lower T2DM risk (RR per SD increase in log-PRL: 0.83; 95% CI, 0.72 - 0.95 in men, and 0.84; 95% CI, 0.71 - 0.98 in women, respectively). An inverse association between PRL and MetS risk was not retained after multivariable adjustment. Longitudinal analyses yielded no association of PRL with incident MetS or T2DM.
CONCLUSION
The present study is the first large population-based study reporting a cross-sectional inverse association between PRL and prevalent T2DM in both genders. But the absent longitudinal associations do not support a causal role of PRL as a risk factor of incident MetS or T2DM.