Proposal for fasting insulin and HOMA-IR reference intervals based on an extensive Brazilian laboratory database

Abstract

Objective: Fasting insulin and the homeostasis model assessment of insulin resistance (HOMA-IR) index are relatively simple and reliable noninvasive markers of insulin resistance (IR). Given the relevance of correctly diagnosing IR, we emphasize the importance of establishing reliable reference intervals (RIs) for these markers. This study aimed to determine the RIs of fasting insulin and HOMA-IR index in adults living in Rio de Janeiro and, secondarily, to verify potential RI differences between sexes. Subjects and methods: Serum insulin levels of 146,497 individuals (ages 20-60 years) who underwent blood sampling in the state of Rio de Janeiro were obtained retrospectively through access to an extensive laboratory database. Insulin was measured using the electrochemiluminescence immunoassay method. After applying exclusion criteria, 21,684 individuals (18,576 [86%] women) were included. The RIs were estimated using a computational mining approach that integrates a selection of R packages. Results: The 95% RIs in women and men and in the overall population were, respectively, 2.54-13.30 μU/mL (15.3-80.12 pmol/L), 2.43-11.89 μU/mL (14.6-71.7 pmol/L), and 2.52-13.14 μU/mL (15.2-79.2 pmol/L) for fasting insulin levels and 0.39-2.86, 0.38-2.81, and 0.39-2.86 for HOMA-IR values. Despite significant differences in insulin levels and HOMA-IR index between men and women, the use of sex-specific RIs was not justified. Conclusion: The RIs of fasting insulin levels and HOMA-IR values found in the overall population can be applied to both sexes. Thus, for our population, we suggest the RIs of 2.52-13.14 μU/mL (15.1-78.8 pmol/L) for fasting insulin and 0.39-2.86 for the HOMA-IR index.

Gut hormones in POTS and their relation to hemodynamic parameters and gastrointestinal symptoms

“…The level of serum insulin was significantly higher in POTS compared with controls (14.8 [11.0–19.2] vs. 11.9 [9.1–15.7] µU/mL; p = 0.029) and slightly elevated according to a large previous study on healthy women, where reference interval was set at 2.54–13.30 µU/mL 37 . After adjustment for sex and age, insulin was still higher in POTS than controls, β = 3.55; 95% CI: 0.39–6.72; p = 0.028.…”

Gut hormones in POTS and their relation to hemodynamic parameters and gastrointestinal symptoms

“…The level of serum insulin was significantly higher in POTS compared with controls (14.8 [11.0–19.2] vs. 11.9 [9.1–15.7] µU/mL; p = 0.029) and slightly elevated according to a large previous study on healthy women, where reference interval was set at 2.54–13.30 µU/mL 37 . After adjustment for sex and age, insulin was still higher in POTS than controls, β = 3.55; 95% CI: 0.39–6.72; p = 0.028.…”

SemaGBA : A System Dynamics Model of the Semaglutide‐Responsive Gut‐Brain Axis A Model of How the Brain and Semaglutide Regulate Appetite and Weight

“…To maintain healthy blood glucose levels during continuous overeating, the model predicts unrealistically high insulin secretion, with fasting insulin levels reaching 93.2 μU/mL. In healthy individuals, fasting insulin typically ranges from 2 to 13 μU/mL [ 44 ], and even postprandial peaks remain below this predicted value (typically ≤ 60 μU/mL) [ 45 , 46 ]. This suggests that improved β‐cell function and insulin sensitivity alone cannot sustain long‐term glucose homeostasis without weight loss.…”

Gut hormones in POTS and their relation to hemodynamic parameters and gastrointestinal symptoms

“…The level of serum insulin was significantly higher in POTS compared with controls (14.8 [11.0–19.2] vs. 11.9 [9.1–15.7] µU/mL; p = 0.029) and slightly elevated according to a large previous study on healthy women, where reference interval was set at 2.54–13.30 µU/mL 37 . After adjustment for sex and age, insulin was still higher in POTS than controls, β = 3.55; 95% CI: 0.39–6.72; p = 0.028.…”

SemaGBA : A System Dynamics Model of the Semaglutide‐Responsive Gut‐Brain Axis A Model of How the Brain and Semaglutide Regulate Appetite and Weight

“…To maintain healthy blood glucose levels during continuous overeating, the model predicts unrealistically high insulin secretion, with fasting insulin levels reaching 93.2 μU/mL. In healthy individuals, fasting insulin typically ranges from 2 to 13 μU/mL [ 44 ], and even postprandial peaks remain below this predicted value (typically ≤ 60 μU/mL) [ 45 , 46 ]. This suggests that improved β‐cell function and insulin sensitivity alone cannot sustain long‐term glucose homeostasis without weight loss.…”

Gut hormones in POTS and their relation to hemodynamic parameters and gastrointestinal symptoms

“…The level of serum insulin was significantly higher in POTS compared with controls (14.8 [11.0–19.2] vs. 11.9 [9.1–15.7] µU/mL; p = 0.029) and slightly elevated according to a large previous study on healthy women, where reference interval was set at 2.54–13.30 µU/mL 37 . After adjustment for sex and age, insulin was still higher in POTS than controls, β = 3.55; 95% CI: 0.39–6.72; p = 0.028.…”

SemaGBA : A System Dynamics Model of the Semaglutide‐Responsive Gut‐Brain Axis A Model of How the Brain and Semaglutide Regulate Appetite and Weight

“…To maintain healthy blood glucose levels during continuous overeating, the model predicts unrealistically high insulin secretion, with fasting insulin levels reaching 93.2 μU/mL. In healthy individuals, fasting insulin typically ranges from 2 to 13 μU/mL [ 44 ], and even postprandial peaks remain below this predicted value (typically ≤ 60 μU/mL) [ 45 , 46 ]. This suggests that improved β‐cell function and insulin sensitivity alone cannot sustain long‐term glucose homeostasis without weight loss.…”