Liu Zhengtao, Que Shuping, Ning Huaijun, Wang Linlin, Peng Tao
Department of Hepatobiliary Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Province, China.
PLoS One. 2013 Dec 4;8(12):e80596. doi: 10.1371/journal.pone.0080596. eCollection 2013.
The incidence of metabolic syndrome (MetS) is rapidly increasing worldwide and associated with alanine aminotransferase (ALT) activity. However, the impact of ALT activity on MetS incidence is inconsistent in published literature. We therefore estimated the association between elevated ALT activity and incident MetS through a meta-analysis of prospective cohort studies.
METHODS/PRINCIPAL FINDINGS: All published prospective cohort studies on the association between elevated ALT activity and incident MetS were retrieved from Pubmed, Embase, and the Institute for Scientific Information (ISI). In all, seven prospective cohort studies, with 31545 participants and 2873 cases of incident MetS were recruited. If there was insignificant heterogeneity (P-value>0.05 and I(2)<50%), the fixed-effect model was used to calculate the pooled relative risks (RRs) of incident MetS induced by raised ALT. Otherwise, the random-effect model was used. The calculated RR was 1.81 (95% confidence interval [CI]: 1.49-2.14) when the incidence of MetS was compared between the highest versus the lowest classification of ALT activities. The pooled RR was 1.13 (95% CI: 1.11-1.16) in dose-response analysis with 5 units per liter (U/l) of ALT increment. Subgroup analysis suggested that gender disparity might be the main origin of heterogeneity in overall analysis (P = 0.007 between RRs of gender-specific subgroups evaluated with 5 U/l increments of ALT). Women had a higher dose-response risk of MetS incidence (1.38, 95% CI: 1.20-1.55) than men. Furthermore, sensitivity analysis confirmed the stability of results. No publication bias was found in our meta-analysis.
CONCLUSIONS/SIGNIFICANCE: Current evidence from prospective studies supports the association between ALT elevation and increasing MetS incidence. This association is closer and more consistent in female population. Further studies are needed to confirm this association and to investigate the potential mechanism of ALT activity on MetS occurrence.
代谢综合征（MetS）在全球的发病率正在迅速上升，且与丙氨酸氨基转移酶（ALT）活性相关。然而，ALT活性对MetS发病率的影响在已发表的文献中并不一致。因此，我们通过对前瞻性队列研究的荟萃分析来估计ALT活性升高与新发MetS之间的关联。
方法/主要发现：从PubMed、Embase和科学信息研究所（ISI）检索了所有已发表的关于ALT活性升高与新发MetS之间关联的前瞻性队列研究。总共纳入了7项前瞻性队列研究，共有31545名参与者和2873例新发MetS病例。如果异质性不显著（P值>0.05且I²<50%），则使用固定效应模型计算ALT升高引起的新发MetS的合并相对风险（RRs）。否则，使用随机效应模型。当比较ALT活性最高与最低分类之间的MetS发病率时，计算出的RR为1.81（95%置信区间[CI]：1.49 - 2.14）。在剂量反应分析中，ALT每增加5单位/升（U/l），合并RR为1.13（95% CI：1.11 - 1.16）。亚组分析表明，性别差异可能是总体分析中异质性的主要来源（以ALT每增加5 U/l评估的性别特异性亚组的RRs之间P = 0.007）。女性发生MetS的剂量反应风险（1.38，95% CI：1.20 - 1.55）高于男性。此外，敏感性分析证实了结果的稳定性。在我们的荟萃分析中未发现发表偏倚。
结论/意义：前瞻性研究的当前证据支持ALT升高与MetS发病率增加之间的关联。这种关联在女性人群中更紧密且更一致。需要进一步的研究来证实这种关联，并研究ALT活性对MetS发生的潜在机制。
