title: Lipoprotein lipase (LPL) mass in preheparin serum reflects insulin sensitivity.
abstract: Lipoprotein lipase (LPL) is one of the enzymes regulated by insulin and its plasma activity reflects insulin sensitivity. Although intravenous heparin injection is required to measure LPL activity, we can detect LPL mass in preheparin serum (Pr-LPL mass) by immunoassay. In this study, we examined whether Pr-LPL mass reflects insulin sensitivity. We measured Pr-LPL mass, insulin sensitivity (Si), and acute insulin release in response to a glucose bolus (AIRg) in subjects with normal glucose tolerance (NGT; n = 23), impaired glucose tolerance (IGT; n = 10), and Type II diabetes mellitus (DM; n = 48). Si and AIRg were determined by minimal model analysis. We also compared Pr-LPL mass with the homeostasis model assessment of insulin resistance (HOMA-R) and the urinary excretion of C-peptide (urine CPR). We found that Pr-LPL mass correlated significantly with Si ( r = 0.354, P < 0.01) in all the subjects. This correlation was still significant in the NGT group (P < 0.472, P < 0.05), DM group (r = 0.311, P < 0.01), and DM group with a fasting plasma glucose >150 mg/dl ( n = 20, r = 0.459. P < 0.05). Moreover, Pr-LPL mass correlated negatively with HOMA-R (r = -0.272. P < 0.05) and fasting IRI (r = -0.256, P < 0.05). By contrast, Pr-LPL mass was not correlated with either urine CPR or logAIRg that reflect the ability to secrete insulin. In conclusion, Pr-LPL mass reflects insulin sensitivity. We speculate that Pr-LPL mass might be used to assess insulin sensitivity not only in the general population but also in advanced diabetic patients.
authors.affiliation: Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi 1-757, Niigata 951-8510, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Hanyu
authors.forename: Takashi
authors.initials: T
authors.lastname: Miida
authors.forename: Konen
authors.initials: K
authors.lastname: Obayashi
authors.forename: Tomoo
authors.initials: T
authors.lastname: Ikarashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Soda
authors.forename: Susumu
authors.initials: S
authors.lastname: Kaneko
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hirayama
authors.forename: Katsunori
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Keiichi
authors.initials: K
authors.lastname: Yamatani
authors.forename: Yoshifusa
authors.initials: Y
authors.lastname: Aizawa
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy / Q000201:enzymology*; D005260:Female; D005951:Glucose Tolerance Test; D006493:Heparin; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood; D007333:Insulin Resistance; D016014:Linear Models; D008071:Lipoprotein Lipase / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D012016:Reference Values; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D006493:Heparin; D008071:Lipoprotein Lipase