title: Serum Uric Acid Levels and Risk of Metabolic Syndrome: A Dose-Response Meta-Analysis of Prospective Studies.
abstract: BACKGROUND
  An excess circulating uric acid level, even within the normal range, is always comorbid with metabolic syndrome (MS), several of its components, and nonalcoholic fatty liver disease (NAFLD), which was regarded as hepatic manifestation of MS; however, these associations remain controversial.
  
  
  OBJECTIVE
  This study aimed to quantitatively assess the relationship between the serum uric acid (SUA) levels and the MS/NAFLD risk.
  
  
  METHODS
  We searched for related prospective cohort studies including SUA as an exposure and MS/NAFLD as a result in MEDLINE (PubMed) and EMBASE databases up to January 31, 2015 and July 28, 2015, respectively. Pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) were extracted. A random-effects model was used to evaluate dose-response relationships.
  
  
  RESULTS
  On the basis of 11 studies (54 970 participants and 8719 MS cases), a combined RR of 1.72 (95% CI, 1.45-2.03; P < .0001) was observed for the highest SUA level category compared with the lowest SUA level category. Furthermore, based on nine studies (51 249 participants and 8265 MS cases), dose-response analysis suggested that each 1 mg/dL SUA increment was roughly linearly associated with the MS risk (RR, 1.30; 95% CI, 1.22-1.38; P < .0001). Beyond that, SUA level increased NAFLD risk (RR, 1.46; 95% CI, 1.31-1.63). Each 1 mg/dL SUA level increment led to 21% increase in the NAFLD risk.
  
  
  CONCLUSIONS
  This meta-analysis suggests that higher SUA levels led to an increased risk of MS regardless of the study characteristics, and were consistent with a linear dose-response relationship. In addition, SUA was also a causal factor for the NAFLD risk.
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Huiping
authors: H
authors: Yuan
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Chenglong
authors: C
authors: Yu
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Xinghui
authors: X
authors: Li
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Liang
authors: L
authors: Sun
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Xiaoquan
authors: X
authors: Zhu
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Chengxiao
authors: C
authors: Zhao
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Zheng
authors: Z
authors: Zhang
authors: Key Laboratory of Geriatrics (H.Y., X.L., L.S., X.Z., C.Z., Z.Z., Z.Y.), School of Public Health (X.L.), Ningxia Medical University, Yinchuan 750011, China; Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China; Mind-Brain Theme (C.Y.), South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, and Australia; and School of Medicine (C.Y.), Flinders University, Adelaide 5042, Australia.
authors: Ze
authors: Z
authors: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000652:urine*; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000652:urine; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014527:Uric Acid / Q000652:urine*; D055815:Young Adult
chemical_list: D014527:Uric Acid