Weight reduction in patients with diabetes via an intensive life-style intervention programme can be maintained for five years and is predicted by patients’ ability to maintain ≥7% weight loss at one-year, found a Harvard study.
An intensive life-style intervention programme for obese patients with diabetes continues to offer health benefits for participants five years after they begin the intervention, a study demonstrates. Participants in the Why WAIT (Weight Achievement and Intensive Management) programme lost substantial amounts of weight, and even those who maintained relatively little loss of weight after five years demonstrated reduced risks of cardiovascular disease.
The study followed 129 Why WAIT participants with an average body-mass index (BMI) of 38 (a BMI higher than 30 is considered obese). Participants showed an average loss of body weight of 9.7% (24 pounds) at the completion of the initial 12-week intervention, and maintained an average loss of 6.4% (16 pounds) at five years.
"This weight loss was very impressive, since we know from previous research that if this population can maintain a 7% weight loss, they show a marked improvement in insulin sensitivity and many other cardiovascular risk factors," says Dr Osama Hamdy, medical director of Joslin's obesity clinical programme and assistant professor of medicine at Harvard Medical School. "To the best of our knowledge, this is the longest follow-up in the real world of clinical practice to show encouraging results that weight loss can be achieved and maintained," adds Hamdy, lead author on a report about the research.
Among Why WAIT participants, the study found, reaching the target 7% weight loss after one year was a good predictor of maintaining weight loss over longer periods. The researchers divided the participants into two groups, depending on whether participants reached that level of weight loss after a year. The group that didn't achieve this goal saw an average weight loss of 3.5% after five years, while the second group (with 53% of participants) maintained an average loss of 9.0% at that time.
These varied results were reflected in measurements of haemoglobin A1C levels. (A1C is a standard assessment of blood glucose levels over two to three months, and people with type 2 diabetes seek to keep their A1C levels below 7.0%.) The higher-weight-loss group saw average A1C levels drop from 7.4% to 6.4% at 12 weeks and then slowly climb to 7.3% over the five-year period. In the lower-weight-loss group, results were not so positive – average A1C decreased from 7.5% to 6.7% at 12 weeks and then rose to 8.0% at five years.
These A1C trends were reflected in patient use of insulin and drugs that help maintain control of blood glucose levels, blood pressure and cholesterol level. Prescriptions of these medications increased significantly among lower-weight-loss participants, but either did not change or dropped in the higher-weight-loss group at five years.
However, the lower-weight-loss group maintained better LDL (bad cholesterol) and HDL (good cholesterol) levels over five years, and their average blood pressure remained unchanged during that time.
The higher-weight-loss group also maintained improvements in their LDL and HDL levels over the length of the study. Additionally, these participants showed lower blood pressure at 18 months, although blood pressure returned to baseline levels after five years.
The Joslin study didn't include a control group of patients, but obese people with type 2 diabetes generally continue to gain weight over time, increasing their risks of cardiovascular damage, Hamdy says.
Launched in 2005, the Why WAIT programme aims to deliver an innovative and achievable combination of nutritional, exercise, medication, learning and monitoring offerings. Among its benefits, for example, "the plan is designed to maintain muscle mass during weight loss so most of the weight loss is from the fat mass, and people will retain high energy expenditure for long-term," Hamdy says. "This study demonstrated that they were able to do this."
In addition to lifestyle interventions, obese patients with diabetes may have the option of weight-loss treatment with medications, gastrointestinal procedures and bariatric surgery. In studies comparing Why WAIT with two common types of surgery, it was found that patients in the intervention programme reported better or equal improvement in quality of life compared with those who underwent surgery, Hamdy says.
Why WAIT is also a good model for diabetes prevention in patients with prediabetes, and for those who are obese without other medical problems, he says. Last year, research on the programme won the American Diabetes Association's Michaela Modan Memorial Award.
"This programme is giving hope to many people with diabetes that there is something that works for weight loss and can work for a long time," he says. "People can maintain their weight loss, and their big benefits in cardiovascular risk factors and diabetes control."
Abstract
Objective: We evaluated long-term impact of sustained weight loss versus weight regain on cardiovascular risk factors in real-world clinical practice.
Methods: We evaluated 129 obese patients with diabetes enrolled in Weight Achievement and Intensive Treatment (Why WAIT) program, a 12-week clinical model of intensive lifestyle intervention. After 1 year, we divided participants into group A, who maintained <7% weight loss (47.3%) and group B (52.7%), who maintained ≥7% weight loss. We continued to follow them for a total of 5 years.
Results: The total cohort lost 23.8 lbs (−9.7%) at 12 weeks and maintained −16.2 lbs (−6.4%) at 5 years (p<0.001). Group A maintained −8.4 lbs (−3.5%) and group B maintained −23.1 lbs (−9.0%) at 5 years. In group A, A1C decreased from 7.5±1.3% to 6.7±0.9% at 12 weeks but increased to 7.7±1.4% at 1 year and 8.0±1.9% at 5 years. In group B, A1C decreased from 7.4±1.2% to 6.4±0.9% at 12 weeks and rose to 6.8±1.2% at 1 year and 7.3±1.5% at 5 years. Despite weight regain, group A maintained improvement in low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol with worsening of serum triglycerides and no change in blood pressure (BP). Group B maintained improvement in lipid profile for 5 years and had significantly lower BP for 18 months.
Conclusions: Weight reduction in patients with diabetes can be maintained for 5 years and is predicted by patients’ ability to maintain ≥7% weight loss at 1 year. A1C and triglycerides deteriorate with weight regain, while other lipid improvements are maintained. Sustained weight loss is associated with significantly lower A1C for 5 years and lowers BP for 18 months.
Authors
Osama Hamdy, Adham Mottalib, Amr Morsi, Nuha El-Sayed, Ann Goebel-Fabbri, Gillian Arathuzik, Jacqueline Shahar, Amanda Kirpitch, John Zrebiec
[link url="http://www.joslin.org/news/cardiovascular-benefits-of-weight-loss-shown-to-continue-for-five-years.html"]Joslin Diabetes Centre material[/link]
[link url="http://drc.bmj.com/content/5/1/e000259"]BMJ Open abstract[/link]