Weight Loss May Improve Glycemic Control and Blood Pressure in Type 2 Diabetes

Patients newly diagnosed with type 2 diabetes who lost weight after the initial diagnosis have improved glycemic control and blood pressure despite weight regain, according to the results of a retrospective cohort study reported in the August 12 Online First issue of Diabetes Care.

"Weight loss in type 2 diabetes is undisputedly important," write Adrianne C. Feldstein, MD, MS, from the Center for Health Research, Kaiser Permanente Northwest, in Portland, Oregon, and colleagues. "Data from community settings describing weight change, and resulting glycemic and blood pressure control, in these patients are limited."

The investigators used electronic medical records to identify 2574 patients 21 to 75 years of age who were newly diagnosed with type 2 diabetes between 1997 and 2002. Growth curve analyses were used to estimate 3-year weight trajectories and cluster analysis to group similar trajectories into 4 categories. The investigators compared category characteristics, and predicted year 4 above-goal hemoglobin A1c (HbA1c) levels and blood pressure by group.

The 4 weight-trajectory groups were higher stable weight (n = 418; 16.2%), lower stable weight (n = 1542; 59.9%), weight gain (n = 300; 11.7%), and weight loss (n = 314; 12.2%). Mean weight loss by 18 months in the weight loss group was 10.7 kg (–9.8%; P < 0.001), but by 36 months there was near-complete weight regain.

The higher stable weight group, lower stable weight group, and weight gain group were more likely than the weight loss group to have above-goal HbA1c levels, after adjustment for age, sex, baseline control, and related medication use. Odds ratios (ORs) were 1.66 (95% confidence interval [CI], 1.12 - 2.47), 1.52 (95% CI, 1.08 - 2.14), and 1.77 (95% CI, 1.15 - 2.72), respectively.

Compared with weight losers, those with higher stable weight or weight gain patterns were more likely to have above-goal blood pressure (OR, 1.83; 95% CI, 1.31 - 2.57; OR 1.47; 95% CI, 1.03 - 2.10), respectively.

"A weight-loss pattern after new diagnosis of type 2 diabetes predicted improved glycemic and blood pressure control despite weight regain," the study authors write. "The initial period post-diagnosis may be a critical time to apply weight loss treatments to improve risk factor control."

Limitations of this study include lack of generalizability to other clinical settings; study only of survivors, precluding knowledge of weight change patterns for others; data collected during clinical care, meaning possibly that weight and other measurements may not have been as precise or complete as they would be during a clinical trial; inability to evaluate possible mechanisms that might explain the improved HbA1c levels and blood pressure control seen in the weight loss group; and lack of data on what behaviors led to weight change.

"In light of previously reported positive effects of weight loss on therapeutic outcomes in people with diabetes, and our added findings of the natural history of weight loss and outcomes in diabetes in the community, more focus should be placed on helping clinicians implement programs to manage weight trajectories in new diabetes patients," the study authors conclude.

The National Institute of Diabetes and Digestive and Kidney Diseases supported this study.

Clinical Context

Obesity, which is highly prevalent in diabetes, is linked to worse control of blood glucose levels and other cardiovascular risk factors. In the Action for Health in Diabetes (Look AHEAD) trial, weight loss in diabetes was associated with improved glycemic control, lowered blood pressure, and improved blood lipid profile.

However, data are limited regarding the extent to which weight loss and resulting levels of glycemic and blood pressure control can be achieved in community-dwelling individuals with type 2 diabetes. The initial period after diabetes is diagnosed is especially important because this may be a time of increased patient and clinician motivation to promote weight loss.

Study Highlights

This retrospective cohort study used electronic medical records data from a health maintenance organization.
The objective of the study was to evaluate weight trajectories in the initial years after a new diagnosis of type 2 diabetes, associated demographic and comorbidity factors, and resulting glycemic and blood pressure control.
The cohort consisted of 2574 patients 21 to 75 years of age who were newly diagnosed with type 2 diabetes between 1997 and 2002.
Growth curve analyses were used to estimate 3-year weight trajectories.
Cluster analysis was used to group similar trajectories into 4 categories: higher stable weight (n = 418; 16.2%), lower stable weight (n = 1542; 59.9%), weight gain (n = 300; 11.7%), and weight loss (n = 314; 12.2%).
Category characteristics were compared, and year 4 above-goal HbA1c levels and blood pressure were predicted by group.
Mean weight loss by 18 months in the weight loss group was 10.7 kg (–9.8%; P < .001), but this group began regaining weight, on average, at approximately 18 months.
By 36 months, there was near-complete weight regain in the weight loss group.
After adjustment for age, sex, baseline control, and related medication use, the higher stable weight group, lower stable weight group, and weight gain group were more likely than the weight loss group to have poor glycemic control, reflected in above-goal HbA1c levels.
ORs for above-goal HbA1c levels were 1.66 (95% CI, 1.12 - 2.47) for the higher stable weight group, 1.52 (95% CI, 1.08 - 2.14) for the lower stable weight group, and 1.77 (95% CI, 1.15 - 2.72) for the weight gain group.
Baseline BMI alone did not significantly predict above-goal HbA1c levels in year 4.
Compared with weight losers, those with higher stable weight or weight-gain patterns were more likely to have above-goal blood pressure (OR, 1.83; 95% CI, 1.31 - 2.57; OR, 1.47; 95% CI, 1.03 - 2.10), respectively.
The investigators concluded that weight loss after a new diagnosis of type 2 diabetes predicted improved glycemic and blood pressure control despite weight regain and that the initial period after diagnosis may be a crucial time to apply weight loss treatments to improve risk factor control.
Study limitations include lack of generalizability to other clinical settings; study only of survivors, precluding knowledge of weight change patterns for others; data collected during clinical care and not during a clinical trial; inability to evaluate possible mechanisms of improved HbA1c levels and blood pressure control in the weight loss group; and lack of data on what behaviors led to weight change.

Pearls for Practice

Approximately 12% of patients newly diagnosed with type 2 diabetes lost weight by 18 months, with mean weight loss nearly 10% of baseline weight. This group began regaining weight, on average, at approximately 18 months; by 36 months, there was near-complete weight regain in the weight loss group.
Weight loss after a new diagnosis of type 2 diabetes predicted improved glycemic control and blood pressure control despite weight regain, suggesting that the initial period after diagnosis may be a crucial time to apply weight loss treatments to improve risk factor control.