Diabetes Complications Predict Worse Quality of Life

Miriam E. Tucker

July 18, 2013

Worsening metabolic control, serious diabetes complications, and the development of psychiatric conditions are the factors leading to worsened quality of life among those with type 1 diabetes in the Diabetes Control and Complications Trial (DCCT) and its long-term follow-up study.

Moreover, those originally assigned to tight glycemic control in DCCT did not suffer reduced quality of life because of the greater burden of treatment, as had originally been feared. Rather, intensive treatment and the subsequent reduction of symptomatic complications helped maintain the long-term quality of life of patients with diabetes.

The findings, from the DCCT's long-term natural-history follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) trial, are published online July 8 in Diabetes Care by Alan M. Jacobson, MD, chief research officer of Winthrop-University Hospital, Mineola, New York, and colleagues.

Dr. Jacobson told Medscape Medical News: "Many people with the intensive intervention don't develop serious complications." Instead, "it is the complications that drive the quality-of-life findings," he stressed.

Longest Prospective Study of Quality of Life in Type 1 Diabetes

In the landmark DCCT, patients with type 1 diabetes randomized to intensive glycemic control had lower rates of diabetes-related complications (N Engl J Med. 1993;329:977-986); the investigators had been concerned that quality of life might worsen in the intensive-treatment group due to the increased burden and greater risk for hypoglycemia. But that turned out not to be true, Dr. Jacobson told Medscape Medical News.

Numerous EDIC analyses — including the most recent ones reported at the American Diabetes Association 2013 Scientific Sessions — have shown ongoing differences in terms of diabetic complications between former participants in the intensive- and conventional-treatment groups despite equalizing of their HbA1c levels. Those originally assigned to tight glycemic control have maintained a benefit in terms of less retinopathy, nephropathy, neuropathy, and other outcomes.

The new EDIC analysis is the longest prospective follow-up study of health-related quality of life in individuals with type 1 diabetes, say Dr. Jacobson and colleagues, noting that previously there has been little information about the long-term effects of treatment modalities or course of illness on life quality.

The report includes data through EDIC year 17, an average of 23.5 years since randomization into the DCCT.

Of the total 1375 surviving DCCT/EDIC participants, 1177 completed Diabetes Quality of Life (DQOL) surveys, which were administered annually during DCCT and every 2 years during EDIC.

Created and validated specifically for the DCCT, the 46-item DQOL has now become a commonly used measure of quality of life for adult patients with diabetes (Diabet Med 2009;26:315-327). The DQOL comprises 4 main subscales: satisfaction, impact, diabetes worry, and social/vocational worry. Scores range from 0 (lowest quality of life) to 100 (highest).

There were no differences in DQOL scores between the original intensive- and conventional-treatment groups at baseline (78 for both groups), end of DCCT (again, 78 for both), or at EDIC year 17 (75 intensive, 74 conventional).

A total 52% of the total DCCT/EDIC study subjects experienced a DQOL "event," defined as a decrement of 5 or more points on 2 consecutive surveys. The rate of events did not differ significantly by DCCT treatment group (P = .9339) but did differ by sex, with males at lower risk of such an event than females (hazard ratio, 0.862; P = .0484).

Complications Worsen Quality of Life

Higher levels of HbA1c, mean blood pressure, and body mass index were all associated with a greater risk for a DQOL event, even after adjustment for age, sex, and education level. Study subjects who experienced severe hypoglycemia also had a 36% increased risk for a DQOL event.

After adjustment, factors significantly associated with lower DQOL scores at EDIC year 17 were development of proliferative diabetic retinopathy or worse (= .0196), nephropathy with albumin excretion rate 300 mg/24 hours or greater or end-stage renal disease (P = .0019), and confirmed clinical neuropathy (P < .0001).

The development of any one of those complications was associated with a significantly lower DQOL score compared with none (73.2 vs 75.2, P = .0009). Participants with all 3 complications had the lowest DQOL scores, with an average of 71.6 (P < .0001 vs no complications).

Also, several specific self-reported symptoms associated with these complications were highly significantly associated with reduced DQOL scores at EDIC year 17, again after adjustment. These included: chest pain (P = .0004); decreased vision in both eyes (P = .0005); paresthesia in the hands or feet (< .0001); urinary incontinence (P = .0001); and male erectile dysfunction (< .0001).

Self-reported history of psychiatric treatment for anxiety or depression was also significantly correlated with lower DQOL scores (< .0001 for both), with a mean adjusted DQOL score of 69.2 for those with both psychiatric conditions.

Dr. Jacobson told Medscape Medical News, "In general, one should assume that the more debilitating and life-limiting, the more the quality-of-life effect. Pain is a major disrupter of quality of life, as well as psychiatric conditions like depression. We have seen that before in other research."

It's Important to Ask About Delicate Subjects

He said patients with diabetes should be asked about quality of life, including delicate issues such as sexual dysfunction.

"I think clinicians should ask both men and women about sexual function as part of periodic visits, just as they ask about other symptoms. They need to be comfortable and have the type of relationship where embarrassing subjects can be brought up. There are ways to bring up concerns with a pattern of questions that works toward the specific. This is [also] an issue for queries about suicide among depressed patients," Dr. Jacobson noted.

Formal questionnaires such as the DQOL or the Short Form 36 Health Survey might be useful to guide such inquiries in clinical practice, although there might not be sufficient time in brief visits, he acknowledged.

The investigators are currently conducting a more in-depth analysis of sexual dysfunction in the DCCT/EDIC population and anticipate presenting preliminary data at the European Association for the Study of Diabetes meeting this fall, Dr. Jacobson told Medscape Medical News.

Abbott, Animas, Aventis, Becton Dickinson, Bayer, Can-AM, Eli Lilly, Lifescan, Medtronic MiniMed, Omron, and Roche contributed free or discounted supplies and/or equipment. The DCCT/EDIC project is supported by contracts with the Division of Diabetes, Endocrinology, and Metabolic Diseases of the National Institute of Diabetes and Digestive and Kidney Diseases, National Eye Institute, National Institute of Neurological Disorders and Stroke, the General Clinical Research Centers Program, the Clinical and Translational Science Awards Program, National Center for Research Resources, and Genentech through a cooperative research and development agreement with the National Institute of Diabetes and Digestive and Kidney Diseases. This work is supported in part by funding from the Herbert Graetz Psychosocial Research Fund (Joslin Diabetes Center) and the Winthrop University Hospital Research Institute. The authors have reported no relevant financial relationships.

Diabetes Care . Published online July 8, 2013. Abstract


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