The effects of age, gender and BMI on outcomes with insulin treatment

This study analyzed the impact of certain patient characteristics on outcomes with insulin treatment for type 2 diabetes. Authors reported significant effects of age, gender, and body weight. Female patients and those in a normal weight category are less likely to achieve treatment goals and may require more clinical attention.

Type 2 diabetes is a progressive disease and typically gets worse slowly over time. Patients with type 2 diabetes initially produce insulin (hormone which lowers blood sugar levels), but it fails to work in the body. Oral antidiabetic drugs, such as metformin (Glucophage), aim to help insulin work in the body. Eventually the pancreas may stop producing insulin. Patients then require insulin therapy. Certain factors, such as age and gender, can impact the outcomes of insulin treatment. More studies are needed to help identify such predictors for appropriate treatment selection.

The aim of this study was to examine the effect of certain patient characteristics on insulin treatment outcomes.

3,188 type 2 diabetes patients were included in this study. Patients were on an oral antidiabetic medication, either metformin (644 patients), a sulfonylurea drug (920), or both (1,624). All patients then received additional insulin treatment for the first time (insulin glargine at a dose of 100U/ml). The effects of factors such as age, gender, BMI (body mass index; a measure of body weight that takes height into account), and oral antidiabetic medications on treatment outcomes were measured over 24 weeks.

Overall, HbA1c levels (a measurement of average blood sugar levels over the past 3 months) decreased from 8.74% at baseline to 7.19% at 24 weeks. 34.7% of patients reached a target fasting plasma glucose (FPG; glucose levels after a period without food or drink) goal of 100 mg/dl or less.

75.6% of patients were older than 65 years and 24.4% were aged 65 years or more. Younger patients had a greater reduction in HbA1c compared with older patients regardless of the type of oral antidiabetic drug. Age did not appear to affect FPG, except for younger patients on metformin, who showed greater reductions.

52.7% of patients were men. Reductions in HbA1c levels from baseline to week 24 were lower in women than in men. Gender did not affect FPG.

BMI category was normal in 11.5%, overweight in 38.1%, and obese in 50.4% patients. Changes in HbA1c were similar across BMI categories. However, fewer patients in the normal BMI category achieved HbA1c of less than 7.0% at week 24 compared to the overweight and obese categories. This pattern was unaffected by the type of oral antidiabetic drug. Larger reductions in FPG were observed in patients with normal BMIs.

Hypoglycemia (low blood sugar) due to insulin treatment was more likely in women and in patients with normal BMIs. The risk of hypoglycemia was similar across the two age groups. Adding insulin treatment to a sulfonylurea drug (alone or in combination with metformin) increased the risk of hypoglycemia risk regardless of age, gender, or BMI.

Authors concluded female patients with type 2 diabetes and those with normal BMIs are less likely to achieve treatment goals when insulin is added to oral antidiabetic treatment. They are also at increased risk of experiencing hypoglycemia following insulin treatment.