Patients with diabetes can have comorbidities that go beyond obesity, hypertension, and dyslipidemia, which should be considered throughout patient management to optimize outcomes.
This Physician’s Weekly feature covering the management of common diabetes comorbidities was completed in cooperation with the experts at the American Diabetes Association.
Throughout the medical literature, it has been well documented that patients with type 2 diabetes are at increased risk for developing cardiovascular disorders, including coronary artery disease and stroke. The constellation of symptoms that includes insulin resistance and obesity greatly increases the likelihood of additional comorbidities emerging. “In addition to the commonly appreciated comorbidities of obesity, hypertension, and dyslipidemia,” says Medha N. Munshi, MD, “diabetes is also associated with other diseases or conditions at rates higher than those of people without diabetes.”
In keeping with patient-centered approaches to care, physicians should be aware of the wide spectrum of comorbidities their patients face when managing them throughout their disease course. When the risk for these comorbidities is elevated, patients should be treated accordingly. The American Diabetes Association reports that some of the more common comorbidities outside the realm of obesity, hypertension, and dyslipidemia include obstructive sleep apnea (OSA), fatty liver disease, cancer, and fractures (Table 1). “Clinicians should consider these other comorbidities during their care of patients with diabetes to optimize outcomes,” says Dr. Munshi.
Obstructive Sleep Apnea
OSA is the most common form of sleep-disordered breathing in patients with type 2 diabetes, accounting for over 80% of cases. In people with diabetes, the prevalence of OSA has been documented to be as high as 23% and the prevalence of some form of sleep disordered breathing may be as high as 58%. “Treating sleep apnea can significantly improve quality of life and blood pressure control,” Dr. Munshi says. “Referral to a sleep specialist should be considered if OSA or any sleep disordered breathing problem is suspected.”
Fatty Liver Disease
Some patients with type 2 diabetes may have unexplained elevated levels of hepatic transaminase concentrations, which in turn can lead to fatty liver disease. Prospective analyses have shown that diabetes has been associated with incident non-alcoholic chronic liver disease and with hepatocellular carcinoma. “In these cases, improving metabolic abnormalities can be beneficial,” says Dr. Munshi. This includes weight loss, glycemic control, and treatment with specific drugs for hyperglycemia or dyslipidemia (Table 2).
Type 2 diabetes has been associated with an increased risk of liver, pancreatic, colorectal, breast, and bladder cancer in published studies. It has been hypothesized that this link may be due to shared risk factors between the diseases, including obesity, age, and physical inactivity. It may also be due to hyperinsulinemia or hyperglycemia. “Patients with diabetes should be encouraged to undergo recommended age- and sex-appropriate cancer screenings,” Dr. Munshi says. “They should also try to reduce their modifiable cancer risk factors, like quitting smoking and increasing their physical activity levels.”
Research has shown that overall fracture risks are significantly higher for both men and women who have type 2 diabetes. The increased risk of hip fracture has been observed despite patients having higher bone mineral density (BMD) levels. Assessing fracture history and risk factors in older patients with diabetes is recommended, and BMD testing should be administered if appropriate for patients’ age and sex. “For at-risk patients,” adds Dr. Munshi, “standard primary or secondary prevention strategies should be considered.”
Other common comorbidities commonly seen in type 2 diabetes are continuing to be evaluated. For example, diabetes has been associated with significantly increased risks for cognitive decline, cognitive impairment, and all-cause dementia. The effects of hyperglycemia and insulin on the brain are areas of intense research interest. Hearing impairment is also more common in people with diabetes, perhaps due to neuropathy and/or vascular disease. Testosterone levels in men with diabetes tend to be lower than those without the disease, and periodontal disease is more severe, but not necessarily more prevalent, in patients with diabetes than those without.
While much of the attention in treating type 2 diabetes has been rightfully directed at managing obesity, hyperglycemia, and hypertension, Dr. Munshi says it is also important for clinicians to keep other common comorbidities in mind during patient care. “The biggest emphasis should be placed on keeping A1C, blood pressure, and cholesterol under control because these strategies will help prevent and treat most comorbidities in diabetes. However, being cognizant of other comorbidities and having a holistic approach to care is also paramount. Collaborating with multidisciplinary care teams is essential. By considering all potential comorbidities, it’s more likely that we will improve quality of life and outcomes in patients with diabetes.”
American Diabetes Association. Standards of Medical Care in Diabetes—2012. Diabetes Care. 2011;35:S11-S63. Available at: http://care.diabetesjournals.org/content/35/Supplement_1/S11.full.
Bainbridge KE, Hoffman HJ, Cowie CC. Diabetes and hearing impairment in the United States: audiometric evidence from the National Health and Nutrition Examination Survey, 1999 to 2004. Ann Intern Med. 2008;149:1-10.
Li C, Ford ES, Zhao G, et al. Prevalence of self-reported clinically diagnosed sleep apnea according to obesity status in men and women: National Health and Nutrition Examination Survey, 2005-2006. Prev Med. 2010;51:18-23.
El-Serag HB, Tran T, Everhart JE. Diabetes increases the risk of chronic liver disease and hepatocellular carcinoma. Gastroenterology. 2004;126:460-468.
Dhindsa S, Miller MG, McWhirter CL, et al. Testosterone concentrations in diabetic and nondiabetic obese men. Diabetes Care. 2010;33:1186-1192.
Darré L, Vergnes JN, Gourdy P, SixouM. Efficacy of periodontal treatment on glycaemic control in diabetic patients: A meta-analysis of interventional studies. Diabetes Metab. 2008;34:497-506.
Suh S, Kim KW. Diabetes and cancer: is diabetes causally related to cancer? Diabetes Metab J. 2011;35:193-198.
Yamamoto M, Yamaguchi T, Yamauchi M, et al. Diabetic patients have an increased risk of vertebral fractures independent of BMD or diabetic complications. J Bone Miner Res. 2009;24:702-709.
Launer LJ, Miller ME, Williamson JD, et al. Effects of intensive glucose lowering on brain structure and function in people with type 2 diabetes (ACCORD MIND): a randomised open-label substudy. Lancet Neurol. 2011;10:969-977.