Does insulin therapy improve longevity in patients with diabetes (diabetes mellitus)?

From the Guidelines

Treating diabetics with insulin can significantly improve longevity, especially for those with Type 1 diabetes, as it is life-saving and can extend life expectancy for many with Type 2 diabetes who require it. Insulin therapy is essential for people with Type 1 diabetes, as their bodies cannot produce this hormone naturally, and without it, diabetic ketoacidosis would develop within days, leading to death 1. For Type 2 diabetics who need insulin, it helps maintain blood glucose control when other medications become insufficient, preventing or delaying serious complications like cardiovascular disease, kidney failure, blindness, and nerve damage that would otherwise shorten lifespan 1.

The longevity benefit comes from insulin's ability to allow glucose to enter cells for energy while preventing toxic high blood sugar levels. Modern insulin regimens, including basal-bolus approaches with long-acting insulins and rapid-acting insulins for meals, have further improved outcomes by better mimicking natural insulin patterns 1. However, the target HbA1c level should be individualized, considering the patient's life expectancy, co-morbidities, and risk of hypoglycemia, with a suggested target of 7.0% for patients at risk of hypoglycemia and with clinically significant co-morbidities or limited life expectancy 1.

Some key points to consider when treating diabetics with insulin include:

• Starting doses for Type 1 diabetics typically range from 0.5-1.0 units/kg/day, divided into multiple doses 1
• Starting doses for Type 2 diabetics who need insulin often range from 0.1-0.2 units/kg/day 1
• The importance of balancing the potential benefits of intensive glycemic control against the risks, particularly in patients with limited life expectancy or significant co-morbidities 1
• The need for individualized target HbA1c levels, taking into account patient-specific factors such as life expectancy, co-morbidities, and risk of hypoglycemia 1

From the Research

Insulin Treatment and Longevity in Diabetics

• The relationship between insulin treatment and longevity in diabetics is complex and influenced by various factors, including the type of insulin, patient health status, and glycemic control 2, 3, 4.
• A study published in 2019 found that insulin use was most prevalent among older individuals with poor health, but subsequent insulin discontinuation after age 75 was most likely in healthier patients 2.
• Another study published in 2018 compared the efficacy and safety of intensive insulin therapy with premixed insulin lispro versus insulin glargine in patients with type 2 diabetes mellitus, and found that premixed insulin lispro provided a larger reduction in HbA1c but was associated with a higher risk of hypoglycemia and weight gain 3.
• A meta-analysis published in 2022 compared the efficiency and safety of insulin degludec/aspart with insulin glargine in type 2 diabetes, and found that insulin degludec/aspart significantly decreased the mean HbA1c level but was prone to serious adverse events, while insulin glargine increased the nocturnal confirmed hypoglycemia events 4.
• A study published in 2022 estimated the potential gains in life expectancy associated with achieving treatment goals in US adults with type 2 diabetes, and found that reducing HbA1c from the fourth quartile to the first was associated with a life expectancy gain of 3.8 years 5.

Factors Influencing Longevity

• Glycemic control is a crucial factor in determining longevity in diabetics, with better control associated with increased life expectancy 5.
• Other factors, such as blood pressure, lipid levels, and body mass index, also play a significant role in determining longevity in diabetics 5.
• The type of insulin used and the patient's health status can also influence longevity, with some insulins associated with a higher risk of hypoglycemia and weight gain 3, 4.

Clinical Implications

• Clinicians should consider the potential benefits and risks of insulin treatment in diabetics, including the impact on longevity 2, 3, 4.
• Achieving treatment goals, such as reducing HbA1c, blood pressure, and lipid levels, can lead to significant gains in life expectancy 5.
• Individualized treatment plans should be developed to balance the benefits and risks of insulin treatment and other interventions, taking into account the patient's health status and other factors 2, 3, 4.