OBJECTIVE -Adiponectin is a plasma protein expressed in adipose tissue. Hypoadiponectinemia is associated with low HDL cholesterol and high plasma triglycerides, which also characterize lipoprotein lipase (LPL) deficiency syndromes. Recently, dramatically increased LPL activity was reported in mice overexpressing adiponectin. We therefore speculated that adiponectin may directly affect LPL in humans. RESULTS -Nondiabetic subjects with decreased plasma adiponectin had lower LPL activity (r ϭ 0.42, P Ͻ 0.0001). This association of plasma adiponectin with LPL activity was confirmed in the second group of patients with type 2 diabetes (r ϭ 0.37, P Ͻ 0.0001). Multivariate analysis revealed that adiponectin was the strongest factor influencing LPL activity, accounting for 23% of the variation in LPL activity in nondiabetic subjects and for 26% of the variation in LPL activity in type 2 diabetic patients. These associations were independent of plasma CRP and HOMA-IR. RESEARCH DESIGN AND METHODSCONCLUSIONS -These results demonstrate an association of decreased postheparin LPL activity with low plasma adiponectin that is independent of systemic inflammation and insulin resistance. Therefore, LPL may represent a link between low adiponectin levels and dyslipidemia in both nondiabetic individuals and patients with type 2 diabetes. Diabetes Care 27:2925-2929, 2004L ipoprotein lipase (LPL) is a pivotal enzyme in lipid metabolism (1). Low LPL activity may be observed in the diabetic dyslipidemia of low HDL cholesterol and high plasma triglycerides (2). Plasma LPL activity has been shown to be decreased in insulin-resistant subjects without diabetes (3), and recently, overall plasma LPL activity was inversely associated with insulin resistance in patients with type 2 diabetes (4). LPL expression is also modulated by systemic inflammation. Tumor necrosis factor (TNF)-␣ and interleukin-6 reduce the expression of LPL at the transcriptional level and decrease LPL activity in plasma (5,6).Adiponectin, the gene product of the apM1 (adipose most abundant gene transcript 1) gene (7), is a member of bioactive substances known as adipocytokines. Adiponectin plasma levels are negatively correlated with BMI (8), insulin resistance (9), and type 2 diabetes (9). Furthermore, adiponectin is associated with lower TNF-␣ expression (10) and has been shown to suppress TNF-␣-induced activation of nuclear transcription factor-B (11), thereby demonstrating antiinflammatory potential. Recently published data suggest that low levels of adiponectin are associated with a lipid profile of low HDL cholesterol and increased plasma triglycerides (12) that is also characteristic for the hypertriglyceridemia in LPL deficiency. LPL is mainly expressed in muscle and adipose tissue (1), the unique source of adiponectin. These findings suggest a direct or indirect relationship between LPL and adiponectin by an unknown mechanism. We therefore investigated, in two different groups of patients, whether adiponectin influences LPL plasma activity and concentration an...

Background-The crucial function of hepatic lipase (HL) in lipid metabolism has been well established, but the relationship between HL activity and coronary artery disease (CAD) is disputed. Methods and Results-We measured HL activity in the postheparin plasma of 200 consecutive men undergoing elective coronary angiography and determined the degree of CAD with the extent score, which has been shown to be better correlated with known risk factors than other measures of CAD extent. We found a significant inverse correlation between HL activity and the extent of CAD (rϭϪ0.19, PϽ0.01). This association was mainly due to patients with HDL levels Ͼ0.96 mmol/L (nϭ94, rϭϪ0.30, PϽ0.005). HL activity was lower in 173 patients with CAD than in 40 controls with normal angiograms (286Ϯ106 versus 338Ϯ108 nmol · mL Ϫ1 · min

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