Insulin is a major therapeutic tool for insulin-deficient patients with type 1 diabetes mellitus, and also for patients with type 2 diabetes mellitus (T2D), with both insulin resistance and a relative insulin deficiency [
Analysis of body composition (BC) changes can help determine whether insulin-induced BW gain can be considered as beneficial or not, by distinguishing the accumulation of fat (FM) from that of fat-free mass (FFM). FFM is an important nutritional parameter, linked with immune competence, functional status, and survival [
The aim of our study was to assess the effects of insulin therapy on body weight and composition, and on muscular strength, in T2D with failure to oral hypoglycaemic agents.
40 type 2 diabetic patients (18 men and 22 women) who presented secondary failure to oral antidiabetic agents with HbA1c > 7% after a duration of 13.5 ± 8.7 years of diabetes mellitus were recruited during their stay in our department. The only inclusion criterion was the introduction of insulin. Exclusion criteria included a reduced autonomy, which could interfere with the plethysmographic measurement, and any condition leading to water and salt retention or any severe concurrent illness.
All T2D were treated with insulin injections and their oral antidiabetic agents. All patients monitored their blood glucose and were asked to adapt the insulin doses in order to obtain HbA1c close to recommended levels [
All patients were fully informed of the purpose of the study and gave their informed consent to take part in the investigation. The university hospital ethics committee accepted the protocol.
At baseline, all patients underwent a physical and laboratory examination to rule out any undercurrent disease. When insulin therapy was indicated, the patients were invited to participate in the study and all accepted. We carried out BC analysis and MS measurements at baseline, then 3 and 6 months later. The baseline analysis was conducted just before starting insulin.
HbA1c was measured on EDTA Vacutainer samples by affinity chromatography using a Hi-AUTOA1c analyzer (A Menarini Diagnostics, Antony Cedex, France) initially and 3 and 6 months later.
BW was measured on an electronic scale to the nearest 0.1 kg and height to the nearest 0.1 cm. Waist circumference (WC) at the umbilical midline was measured to the nearest mm with flexible tape.
Air displacement plethysmographic measurements were carried out using the Bod-Pod body composition system (Life Measurement, Inc, Concord, Calif, USA) according to the manufacturer's recommendations [
Three consecutive measurements of handgrip strength with the dominant hand were performed with a calibrated dynamometer (Takei Scientific Instruments, Tokyo, Japan), which was reset to zero before each measurement. The measurements were conducted under standardized conditions: subject seated, the shoulder adducted and neutrally rotated, with the elbow at
Data are shown as means with standard deviations. SPSS software 10.0.5 was used for the calculations (standard version, copyright Ó SPSS Inc. 1989–1999). A one-way analysis of variance for repeated measures over time (ANOVA) was used to compare the values at baseline (M0), 3 months (M3), and 6 months (M6). Associations were tested by linear regression.
The T2D were 62 ± 12 years, their BW was stable over the previous three months: BW 85.4 ± 14.7 kg: BMI 30.9 ± 5.7 kg/
HbA1C improved during the first three months, and then stabilized. M6 HbA1c: 7.56 ± 0.8%. The doses of insulin tended to increase from M0 to M6.
BW increased on insulin treatment to 88.5 ± 14 kg, and 75% of the increase occurred after 3 months. The composition of the BW gain: during the first three months FM and FFM were unchanged, but at six months, FM increased
MS was correlated with FFM (
In this study, we studied the progression of BW, BC, and MS during six months after starting insulin therapy in 40 T2D. Insulin induced a significant decrease in HbA1C, that approached the recommended level in type 2 diabetes (7.5± 0.9%). The course and nature of the BW gain was +3.1 ± 2.2 kg at M6 and 75% of the increase occurred after M3. All the weight gain was due to FM (+3.1 ± 2.7 kg), whereas FFM was unchanged (
One limitation of our study stems from the use of a two-compartment model for the analysis of BC by air displacement plethysmography (ADP), as hydration of FFM cannot be assumed to be constant during insulin therapy. Overall our results are in agreement with previous studies. In T2D, previous studies reported that BW gain (+1.6 ± 4.9 to +5.2 ± 2.7 kg at six months) was mainly composed of fat [
Our study did not aim to explain the progression of BC during insulin treatment, but several studies investigating the role of insulin on protein metabolism in diabetes mellitus have provided useful data. In type 1 diabetes, protein turnover studies using isotopically labeled amino acid tracers have demonstrated that protein breakdown and amino acid oxidation are increased in the insulin-deprived state, and are normalized by insulin, which has an anticatabolic effect [
Insulin therapy is clearly beneficial for glycemic control in T2D but we do not feel that the gain in FM offsets this benefit. However, the excess fat is deposited essentially in the intra-abdominal area [
In summary, BW gain of TD2 on insulin therapy was 3.1 ± 2.2 kg, it was predominantly fat with no improvement in muscular strength or FFM.
Evolution from M0 to M6 of body parameters and Hb1Ac levels during insulin therapy in patients with type 2 diabetes mellitus. Results are mean (SD),
3 months (M3) | 6 months (M6) | |
---|---|---|
Weight change (kg) | + 0.7 (2.3) | + 3.1 (2.2) |
Fat mass change (kg) | + 3.1 (2.7) | |
Waist circumference change (cm) | + 1.7 (4.5) | |
Fat free mass change (kg) | + 0.9 (2.9) | |
Muscle strength change (kg) | + 0.4 (2.9) | + 0.4 (4.2) |
HbA1c change (%) | ||
Insulin doses (U/kg) | 0.41 (0.32) | 0.44 (0.27) |
Air displacement Plethysmography
Body composition
Body Weight
Fat-free mass
Fat mass
Muscular strength
patients with type 2 diabetes mellitus
Waist Circumference.
This work was supported by a grant from the ALFEDIAM, and the Institut de Recherche en Nutrition Humaine en Aquitaine. We would like to thank Dr. S. Jarman for revision of the English manuscript.