Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, 750 07, Uppsala, Sweden.
University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden.
BMC Vet Res. 2021 Jan 18;17(1):34. doi: 10.1186/s12917-020-02729-1.
Obesity is associated with insulin resistance (IR) and considered a risk factor for diabetes mellitus (DM) in cats. It has been proposed that homeostasis model assessment (HOMA-IR), which is the product of fasting serum insulin (mU/L) and glucose (mmol/L) divided by 22.5, can be used to indicate IR. The objectives of this study were threefold: (i) to evaluate associations between body fat, fasting insulin, and HOMA-IR, (ii) to determine population-based reference interval of HOMA-IR in healthy lean cats, and (iii) to evaluate biological variation of HOMA-IR and fasting insulin in cats.
150 cats were grouped as lean or overweight based on body condition score and in 68 of the cats body fat percentage (BF%) was estimated by computed tomography. Fasting serum insulin and glucose concentrations were analysed. Statistical differences in HOMA-IR and insulin between overweight or lean cats were evaluated using Wilcoxon rank-sum test. Robust method with Box-Cox transformation was used for calculating HOMA-IR reference interval in healthy lean cats. Relations between BF% and HOMA-IR and insulin were evaluated by regression analysis. Restricted maximum likelihood ratio was used to calculate indices of biological variation of HOMA-IR and insulin in seven cats. There were significant differences between groups with overweight cats (n = 77) having higher HOMA-IR (p < 0.0001) and insulin (p = 0.0002) than lean cats (n = 73). Reference interval for HOMA-IR in lean cats was 0.1-3.0. HOMA-IR and fasting insulin concentrations showed similar significant positive association with BF% (p = 0.0010 and p = 0.0017, respectively). Within-animal coefficient of variation of HOMA-IR and insulin was 51% and 49%, respectively.
HOMA-IR and fasting insulin higher in overweight than lean cats and correlate to BF%. The established population-based reference interval for HOMA-IR as well as the indices of biological variation for HOMA-IR and fasting insulin may be used when interpreting HOMA-IR and fasting insulin in cats. Further studies are needed to evaluate if HOMA-IR or fasting insulin is useful for identifying cats at risk of developing DM.
肥胖与胰岛素抵抗（IR）有关，被认为是猫患糖尿病（DM）的危险因素。有人提出，稳态模型评估（HOMA-IR），即空腹血清胰岛素（mU/L）和葡萄糖（mmol/L）的乘积除以 22.5，可以用来表示 IR。本研究的目的有三：（i）评估体脂、空腹胰岛素和 HOMA-IR 之间的关系，（ii）确定健康瘦猫的 HOMA-IR 人群参考区间，（iii）评估 HOMA-IR 和空腹胰岛素在猫中的生物学变异。
根据体况评分，将 150 只猫分为瘦或超重组，其中 68 只猫通过计算机断层扫描估计体脂肪百分比（BF%）。分析空腹血清胰岛素和葡萄糖浓度。使用 Wilcoxon 秩和检验评估超重或瘦猫之间 HOMA-IR 和胰岛素的统计学差异。使用稳健方法和 Box-Cox 转换计算健康瘦猫的 HOMA-IR 参考区间。通过回归分析评估 BF%与 HOMA-IR 和胰岛素的关系。在 7 只猫中使用受限最大似然比计算 HOMA-IR 和胰岛素的生物学变异指数。超重猫（n=77）的 HOMA-IR（p<0.0001）和胰岛素（p=0.0002）均显著高于瘦猫（n=73），两组间存在显著差异。瘦猫的 HOMA-IR 参考区间为 0.1-3.0。HOMA-IR 和空腹胰岛素浓度与 BF%呈显著正相关（p=0.0010 和 p=0.0017）。HOMA-IR 和胰岛素的个体内变异系数分别为 51%和 49%。
超重猫的 HOMA-IR 和空腹胰岛素高于瘦猫，与 BF%相关。本研究建立的 HOMA-IR 人群参考区间以及 HOMA-IR 和空腹胰岛素的生物学变异指数，可用于解释猫的 HOMA-IR 和空腹胰岛素。需要进一步研究以评估 HOMA-IR 或空腹胰岛素是否有助于识别患 DM 风险的猫。
