• Metabolic symptoms: weight gain, difficulty losing weight or central weight distribution.
• Fatigue: persistent tiredness or reduced energy levels.
• Abnormal lipid markers: raised cholesterol or triglycerides.
• Blood sugar concerns: suspected pre-diabetes or diabetes.
• Cardiovascular risk factors: high blood pressure or family history of heart disease.
• Polycystic ovary syndrome: metabolic assessment in PCOS.
• Appetite changes: excessive hunger or cravings.
• Glycaemic symptoms: frequent urination, excessive thirst or blurred vision.

Fasting Insulin measures circulating insulin levels using a fasting bloodspot sample. Insulin is a key hormone involved in regulation of blood glucose and energy storage, and fasting levels provide insight into baseline insulin activity.

Clinically, this test may be useful when exploring metabolic symptoms, cardiometabolic risk factors or blood sugar-related concerns. Elevated fasting insulin levels may be observed before changes in fasting glucose become apparent, offering additional context when reviewing metabolic health.

Practitioners typically interpret fasting insulin results alongside glucose markers, lipid profiles, body composition, lifestyle factors and other relevant laboratory findings. When reviewed in context, the test can support informed discussions with clients about insulin-related metabolic patterns.

Practical

Specimen requirements:

Bloodspot

Average processing time:

10 - 14 days

Research regarding vailidity (what is tested for)

• Albarrak AI, Luzio SD, Chassin LJ, et al. Associations of glucose control with insulin sensitivity and pancreatic beta-cell responsiveness in newly presenting type 2 diabetes. J Clin Endocrinol Metab 2002;87:198-203.

• Baltali M, Korkmaz ME, Kiziltan HT, et al. Association between postprandial hyperinsulinemia and coronary artery disease among nondiabetic women: a case control study. Int J Cardiol 2003;88:215-21.

• Karabulut A, Iltumur K, Toprak N, et al. Insulin response to oral glucose loading and coronary artery disease in nondiabetics. Int Heart J 2005;46:761-70.

• Laakso M. How good a marker is insulin level for insulin resistance? Am. J. Epidemiol., 1993; 137: 959- 965.

• Shim WS, Kim SK, Kim HJ, et al. Decrement of postprandial insulin secretion determines the progressive nature of type-2 diabetes. Eur J Endocrinol 2006;155:615-22.

Research regarding reliability (methodology used)

• Buttler N, et al. Development of a bloodspot assay for insulin. Clinica Chimica Acta., 2001; 310: 141-150.

• Dowlati. B, Dunhardt. P et. Al. Quantification of insulin in dried blood spots. J. Lab. Clin. Med., 1998; 131: 370.