Glucose-dependent insulinotropic polypeptide (GIP) plays an important role in the glucose and lipid metabolism. We investigated the effects of exogenous GIP on lipid metabolism during time of stable insulin levels. Ten male patients with type 1 diabetes without endogenous insulin secretion (C-peptide-negative, mean [±SD] age 26 ± 4years, body mass index 24 [±2] kg/m², glycated haemoglobin 56 [±8] mmol/mol or 7.3 [±0.8]%) were studied in a randomized, double-blind, placebo-controlled, crossover study with continuous intravenous infusions of GIP (4 pmol/kg/min) or placebo (saline), during two separate 90-minute hyperglycaemic (12 mmol/L) clamps with basal insulin substitution (0.1-0.2 mU/kg/min). Plasma glycerol concentrations increased from baseline during GIP infusion and decreased during placebo infusion (baseline-subtracted area under the curve [bsAUC] 703 ± 407 vs. −262 ± 240 μmol/L × min, respectively; P < 0.001). Free fatty acids (FFAs) increased during GIP infusions (bsAUC 5505 ± 2170 μEq/L × min) and remained unchanged during placebo infusion (bsAUC −74 ± 2363 μEq/L × min), resulting in a significant difference between GIP and placebo infusions (P < 0.001). Plasma concentrations of glucose, insulin, glucagon-like peptide-1 and glucagon were similar during GIP and placebo infusions. GIP increased plasma glycerol and FFAs in patients with type 1 diabetes during hyperglycaemia and stable basal insulin levels. This supports a direct lipolytic effect of GIP at high glucose and low levels of plasma insulin.

中文翻译：

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葡萄糖依赖性促胰岛素多肽在 1 型糖尿病患者稳定基础胰岛素替代和高血糖期间诱导脂肪分解：一项随机、双盲、安慰剂对照、交叉临床试验

葡萄糖依赖性促胰岛素多肽（GIP）在糖脂代谢中起重要作用。我们研究了在胰岛素水平稳定期间外源性 GIP 对脂质代谢的影响。10 名男性 1 型糖尿病患者，无内源性胰岛素分泌（C 肽阴性，平均 [±SD] 年龄 26 ± 4 岁，体重指数 24 [±2] kg/m ², 糖化血红蛋白 56 [±8] mmol/mol 或 7.3 [±0.8]%) 在一项随机、双盲、安慰剂对照、交叉研究中进行了研究，其中连续静脉输注 GIP (4 pmol/kg/min) 或安慰剂（盐水），在两个单独的 90 分钟高血糖 (12 mmol/L) 钳夹期间，基础胰岛素替代 (0.1-0.2 mU/kg/min)。血浆甘油浓度在 GIP 输注期间从基线增加，在安慰剂输注期间降低（基线减去曲线下面积 [bsAUC] 分别为 703 ± 407 与 -262 ± 240 μmol/L × min；P  < 0.001）。游离脂肪酸 (FFA) 在 GIP 输注期间增加（bsAUC 5505 ± 2170 μEq/L × min），在安慰剂输注期间保持不变（bsAUC -74 ± 2363 μEq/L × min），导致 GIP 和安慰剂输注之间存在显着差异(磷 < 0.001)。在 GIP 和安慰剂输注期间，葡萄糖、胰岛素、胰高血糖素样肽-1 和胰高血糖素的血浆浓度相似。在高血糖和稳定的基础胰岛素水平期间，GIP 增加了 1 型糖尿病患者的血浆甘油和 FFA。这支持 GIP 在高葡萄糖和低水平血浆胰岛素下的直接脂解作用。