title: Latent associations of low serum amylase with decreased plasma insulin levels and insulin resistance in asymptomatic middle-aged adults.
abstract: BACKGROUND
  Low serum amylase is likely to be associated with obesity and metabolic abnormalities, which are often accompanied by impaired insulin action. However, it is unclear whether low serum amylase is associated with impaired insulin action in clinical settings. Therefore, we investigated the associations of low serum amylase with plasma insulin levels, and obesity-related parameters, including leptin.
  
  
  METHODS
  We measured serum amylase, plasma insulin, obesity-related parameters such as leptin, cardiometabolic risk factors, and anthropometric parameters in a cross-sectional study of 54 asymptomatic subjects (mean age 48.6 ± 7.6 years) who were not being treated for diabetes.
  
  
  RESULTS
  Body mass index (BMI) and plasma glucose at 120 min after a 75-g oral glucose tolerance test (OGTT) were significantly higher in subjects with low serum amylase (< 60 IU/l, n = 21) than in those with normal-to-high serum amylase (n = 33) (P = 0.04 and P = 0.004, respectively). In univariate correlation analysis, serum amylase was significantly correlated with BMI alone (r = -0.39, P = 0.004). By contrast, multivariate logistic analysis showed that each 1-SD increase in quantitative insulin sensitivity check index, and each 1-SD decrease in plasma insulin OGTT at 0 and 60 min, homeostasis model assessment of insulin resistance (HOMA)-R, and HOMA-β were significantly associated with low serum amylase, particularly after adjusting for BMI. When subjects were divided into three groups according to HOMA-R, serum amylase levels were significantly lower in subjects with HOMA-R > 2.5 (n = 23) compared with subjects with HOMA-R 1.6-2.5 (n = 10) (61.1 ± 13.6 U/ml versus 76.9 ± 20.5 U/ml, Bonferroni test, P = 0.02), but not compared with subjects with HOMA-R<1.6 (n = 21; 62.7 ± 17.6 U/ml). Similar trends were observed when subjects were divided according to plasma leptin and fasting plasma insulin levels.
  
  
  CONCLUSIONS
  These results suggest that after adjusting for BMI, low serum amylase is associated with decreased basal insulin levels and insulin secretion, as well as high insulin resistance. The nature of these associations remains to be elucidated in further studies.
authors: First Department of Comprehensive Medicine, Saitama Medical Center, Jichi Medical University School of Medicine, 1-847 Amanuma, Omiya, Saitama 330-8503, Japan.
authors: Toshitaka
authors: T
authors: Muneyuki
authors: Kei
authors: K
authors: Nakajima
authors: Atsushi
authors: A
authors: Aoki
authors: Masashi
authors: M
authors: Yoshida
authors: Hiroshi
authors: H
authors: Fuchigami
authors: Hiromi
authors: H
authors: Munakata
authors: San-E
authors: SE
authors: Ishikawa
authors: Hitoshi
authors: H
authors: Sugawara
authors: Masanobu
authors: M
authors: Kawakami
authors: Shin-Ichi
authors: S
authors: Momomura
authors: Masafumi
authors: M
authors: Kakei
mesh_terms: D000328:Adult; D000681:Amylases / Q000097:blood*; D044466:Asian People; D058070:Asymptomatic Diseases; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D015536:Down-Regulation; D005260:Female; D044882:Glucose Metabolism Disorders / Q000097:blood* / Q000208:ethnology; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000208:ethnology; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000097:blood / Q000208:ethnology; D016017:Odds Ratio; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
chemical_list: D015415:Biomarkers; D007328:Insulin; D000681:Amylases