Normal blood insulin levels
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Understanding Normal Blood Insulin Levels
Introduction to Blood Insulin Levels
Insulin is a crucial hormone for regulating blood glucose levels. Understanding normal insulin levels is essential for diagnosing and managing conditions like diabetes. This article synthesizes research findings on normal blood insulin levels, focusing on various contexts such as healthy individuals, children, and critically ill patients.
Normal Insulin Levels in Healthy Individuals
In healthy individuals, insulin levels fluctuate throughout the day, particularly in response to meals. A study measuring serum insulin levels after the administration of exogenous insulin found that peak concentrations of serum insulin were around 26.2 ± 2.9 μU/ml 60 minutes after injecting 10 units of regular insulin2. This study highlights the variability in insulin levels depending on the type and timing of insulin administration.
Insulin Levels in Children
Research on pre-pubertal children from the IDEFICS cohort provides age- and sex-specific reference values for insulin levels. The study found that median serum insulin levels ranged from 17.4 pmol/l in 3- to 3.5-year-old girls to 53.5 pmol/l in 10.5- to 11-year-old girls. Boys had slightly lower median values, ranging from 13.2 pmol/l to 43.0 pmol/l in the same age groups3. These findings indicate that insulin levels increase with age and are generally higher in girls than boys.
Insulin Levels in Critically Ill Patients
Critically ill patients often experience hyperglycemia and insulin resistance, even without a prior history of diabetes. Intensive insulin therapy, aiming to maintain blood glucose levels between 80 and 110 mg/dl, has been shown to improve clinical outcomes significantly. Studies have demonstrated that such therapy can reduce mortality, bloodstream infections, acute renal failure, and the need for prolonged mechanical ventilation1 4 7. These findings underscore the importance of maintaining tight glycemic control in critically ill patients.
Insulin Sensitivity and Resistance
Insulin sensitivity indices, such as ISI(gly) and ISI(ffa), can be calculated using basal and OGTT-induced insulin, glucose, and FFA levels. These indices help assess whole-body insulin sensitivity under physiological conditions. Research indicates that these indices are reduced in overweight individuals, those with impaired glucose tolerance (IGT), and non-insulin-dependent diabetes mellitus (NIDDM) patients and their relatives5. This highlights the variability in insulin sensitivity among different populations.
Conclusion
Normal blood insulin levels vary based on age, sex, health status, and physiological conditions. In healthy individuals, insulin levels peak after meals and vary throughout the day. Children show increasing insulin levels with age, with higher levels in girls. Critically ill patients benefit from intensive insulin therapy to maintain tight glycemic control, which improves clinical outcomes. Understanding these variations is crucial for diagnosing and managing insulin-related disorders effectively.
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Most relevant research papers on this topic
Intensive insulin therapy in the medical ICU – not so sweet?
Intensive insulin therapy in the medical ICU is associated with increased mortality and morbidity compared to conventional therapy.
RCT
Rigorous JournalSerum insulin levels following administration of exogenous insulin.
Serum insulin levels in insulin-deficient diabetic patients vary significantly from healthy subjects, highlighting the difficulty in maintaining normal blood sugar levels.
Non-RCTPercentiles of fasting serum insulin, glucose, HbA1c and HOMA-IR in pre-pubertal normal weight European children from the IDEFICS cohort
This study provides age- and sex-specific reference values for insulin, glucose, HbA1c, and HOMA-IR in pre-pubertal European children, with higher insulin and HOMA-IR values in girls and slightly higher glucose values in boys.
Observational StudyRigorous Journal
Highly CitedImplementation of a safe and effective insulin infusion protocol in a medical intensive care unit.
Our nurse-implemented insulin infusion protocol is safe and effective in improving glycemic control in critically ill patients, with minimal physician input.
RCTRigorous JournalHighly CitedInsulin sensitivity indices calculated from basal and OGTT-induced insulin, glucose, and FFA levels.
Insulin sensitivity indices (ISI(gly) and ISI(ffa)) are reduced in overweight individuals, individuals with impaired glucose tolerance, and NIDDM patients and their relatives.
Meta-AnalysisHighly CitedDiabetes due to secretion of an abnormal insulin.
This patient's diabetes is likely due to a structural abnormality in his circulating insulin, with impaired biologic activity on rat adipocytes.
Case ReportHighly CitedIntensive insulin therapy in critically ill patients.
Intensive insulin therapy to maintain blood glucose levels below 110 mg per deciliter reduces morbidity and mortality in critically ill patients in the surgical intensive care unit.
RCT
Large Human TrialHighly CitedWhat is a normal blood glucose?
Normal blood glucose levels in infants, children, and adults range from 3.5 to 5.5 mmol/L, with factors controlling glucose production and utilization playing a key role in maintaining this range.
Highly CitedSafety and feasibility of an insulin adjustment protocol to maintain blood glucose concentrations within a narrow range in critically ill patients in an Australian level III adult intensive care unit.
The insulin adjustment protocol with a constant caloric source and frequent blood glucose level monitoring is safe and feasible for maintaining blood glucose concentrations within a narrow range in adult intensive care unit patients.
Observational StudyJet Injection of Insulin During Self-Monitoring of Blood Glucose
Jet injections of insulin effectively maintain blood glucose levels in individuals with insulin-dependent diabetes mellitus, resulting in blood glucose levels generally within 60 and 150 mg/dl.
Highly Cited