Replication data for: Correlations between modest weight loss and leptin to adiponectin ratio, insulin and leptin resensitization in a small cohort of Norwegian individuals with obesity.

The present dataset is the basis of the results presented in \"Modest weight loss improves leptin to adiponectin ratio and induces insulin and leptin resensitivization in individuals with obesity.\" (manuscript submitted 2019, December). Please read the accompanying ReadMe file for a further description of variables.
Abstract: Background: Identifying patients at the highest risk of adverse consequences of obesity is of great importance in order to better monitor the effects of treatment. This study aims to investigate whether dysregulated adipokines and postprandial triglycerides (TG) improve with modest weight loss. Methods: Individuals with obesity were recruited by posters, among patients at the University Hospital of North Norway and the Stamina Health weight loss program. We calculated the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), leptin to adiponectin (L:A) ratio, indirect leptin sensitivity (REE:leptin ratio), postprandial TG clearance at 6 h and TG response from samples collected at visits before and after weight loss. The weight loss goal was ≥5% of initial total weight. Results: Twenty-eight participants attended both assessments, of which 13 lost ≥5% body weight. Of these, five lost ≥10% body weight. HOMA-IR (-23.1%), REE:leptin ratio (+80.1%) and L:A ratio (-45.7%) significantly improved with a weight loss ≥5%, whereas there was no improvement of postprandial TG response or clearance. Participants with ≥5% weight loss improved their L:A ratio over cut-off values ≥1.88 and ≥2.2 significantly, and participants with ≥10% weight loss improved their L:A ratio over the cut-off value ≥3.65 significantly. Participants with ≥10% weight loss also improved their HOMA-IR over cut-off value ≥2.3 significantly. Conclusion: Metabolic dysregulation measured by the surrogate biomarkers HOMA-IR, REE:leptin ratio and L:A ratio, but not postprandial TG, improve with a modest weight loss of ≥ 5%. Further improvements in these biomarkers are seen in weight loss of ≥10%.
To measure postprandial TG response (TGR) and TG clearance, we performed an Oral Fat Tolerance Test (OFTT). Participants had their regular diet and abstained from vigorous exercise three days before the test, and showed up at 08:00 am after a 12 h overnight fast. Fasting blood samples were drawn, and a meal of sour cream porridge was served, containing 1 g of fat per kg of body weight (28). The participants ingested the meal within 30 minutes, and blood samples were drawn from the antecubital vein in a seated position at baseline and 2, 4, 6 and 8 h postprandially. We calculated TG clearance in per cent of the peak value at 6 and 8 h, in addition to the TGR, defined as the average of the two highest postprandial TG concentrations, minus the baseline concentration. The formula for calculating TG clearances (28) at time X was as follows: Clearance Xh =100×(1- ([TG]X -[TG]0h)/([TG]max -[TG]0h )) We performed a 2 h Oral Glucose Tolerance Test (OGTT) on a separate day. Preparations for the OGTT were the same as for the OFTT and was conducted by oral intake of 75 g glucose, dissolved in water. We collected blood samples in both the fasting state and 30, 60, 90 and 120 minutes after glucose intake, in which serum glucose and serum insulin were measured using ELISA kits (DRG Insulin Elisa kit, DRG Instruments GmbH, Germany). We determined insulin sensitivity by calculation of the HOMA1-IR. Both s-leptin and free s-adiponectin were analysed from frozen serum drawn at all sample times, both during OFTT and OGTT, using ELISA kits (DRG Diagnostics, Marburg, Germany) for s-leptin (sandwich ref. EIA-2395) and s-adiponectin (human, ref. EIA-4574), respectively. Leptin sensitivity was calculated as the ratio of Resting Energy Expenditure (REE) to fasting serum leptin. We performed REE measurements by a canopy test with an indirect calorimetry device from Medical Graphics CPX metabolic cart (St Paul, MN, USA). The test protocol is described by Larsen et al. Leptin to adiponectin ratio – A surrogate biomarker for early detection of metabolic disturbances in obesity. Nutrition, Metabolism and Cardiovascular Diseases. 2018. After the completion of REE measurement, the OGTT was performed. We used parametric tests on raw or transformed variables that resembled a normal distribution visually or by skewness/kurtosis. Otherwise, non-parametric tests were performed.

本数据集是发表于《适度减重改善瘦素（leptin）与脂联素（adiponectin）比值并诱导肥胖人群胰岛素及瘦素复敏》（2019年12月投稿的手稿）中研究结果的基础数据。请查阅随附的ReadMe文件以获取变量的详细说明。

摘要：背景：识别肥胖相关不良结局风险最高的患者，对于优化治疗监测具有重要意义。本研究旨在探讨适度减重是否可改善脂肪因子失调及餐后甘油三酯（triglycerides, TG）异常。
方法：研究对象为挪威北部大学医院及Stamina Health减重项目中的肥胖患者，通过海报招募。我们计算了胰岛素抵抗稳态模型评估（Homeostasis Model Assessment of Insulin Resistance, HOMA-IR）、瘦素/脂联素（L:A）比值、间接瘦素敏感性（静息能量消耗（Resting Energy Expenditure, REE）/瘦素比值，REE:leptin ratio）、6小时餐后TG清除率及减重前后访期采集样本中的TG应答水平。本次研究的减重目标为初始体重的≥5%。
结果：共计28名受试者完成两次评估，其中13名受试者体重降幅≥5%，5名受试者体重降幅≥10%。当体重降幅≥5%时，HOMA-IR（下降23.1%）、REE:leptin比值（上升80.1%）及L:A比值（下降45.7%）均得到显著改善，但餐后TG应答及清除率无明显变化。体重降幅≥5%的受试者，其L:A比值显著突破临界值1.88及2.2；体重降幅≥10%的受试者，其L:A比值显著突破临界值3.65，且HOMA-IR显著突破临界值2.3。
结论：通过替代生物标志物HOMA-IR、REE:leptin比值及L:A比值评估的代谢失调，可在≥5%的适度减重后得到改善，且在≥10%的减重幅度中可获得进一步提升，而餐后TG水平无此类改善。

为测量餐后TG应答（TG response, TGR）及TG清除率，我们开展了口服脂肪耐受试验（Oral Fat Tolerance Test, OFTT）。受试者需在试验前3日保持常规饮食，避免剧烈运动，并于试验当日晨起8:00时抵达，保持12小时夜间空腹状态。首先采集空腹血样，随后给予受试者酸奶油粥作为试验餐，按每公斤体重1g脂肪的标准配置（28）。受试者需在30分钟内进食完毕，并于基线及餐后2、4、6、8小时取坐位时经肘前静脉采集血样。我们以百分比形式计算6小时及8小时的TG清除率，同时计算TGR：TGR定义为餐后两次最高TG浓度的平均值减去基线浓度。X时间点TG清除率的计算公式如下（28）：Clearance Xh =100×(1- ([TG]X -[TG]0h)/([TG]max -[TG]0h ))

我们于另一天开展了2小时口服葡萄糖耐量试验（Oral Glucose Tolerance Test, OGTT）。OGTT的准备流程与OFTT一致，受试者需口服溶解于水中的75g葡萄糖。分别于空腹状态及葡萄糖摄入后30、60、90、120分钟采集血样，采用酶联免疫吸附试验（Enzyme-Linked Immunosorbent Assay, ELISA）试剂盒（德国DRG Instruments GmbH公司DRG胰岛素ELISA试剂盒）检测血清葡萄糖及血清胰岛素水平。我们通过HOMA1-IR计算胰岛素敏感性。

所有采样时点（包括OFTT及OGTT）采集的冰冻血清样本，均采用ELISA试剂盒分别检测总瘦素（s-leptin）及游离脂联素（free s-adiponectin）：总瘦素检测使用DRG Diagnostics（德国马尔堡）的夹心法试剂盒（货号EIA-2395），游离脂联素检测使用人源试剂盒（货号EIA-4574）。瘦素敏感性以静息能量消耗（REE）与空腹血清瘦素的比值计算。我们采用Medical Graphics CPX代谢车（美国明尼苏达州圣保罗市）的间接测热仪进行面罩法REE测量，测试方案参考Larsen等发表于《Nutrition, Metabolism and Cardiovascular Diseases》2018年的文章《Leptin to adiponectin ratio – A surrogate biomarker for early detection of metabolic disturbances in obesity.》。REE测量完成后，随即开展OGTT。

对于视觉上符合正态分布或经偏度/峰度检验符合正态分布的原始变量或转换后变量，我们采用参数检验；其余情况则采用非参数检验。