Healthcare systems around the world face a growing challenge of managing populations with multiple co-existent chronic conditions, including diabetes. On an individual level, multimorbidity can have a profound effect on a patient’s ability to self care and balance different treatment needs across multiple conditions.
The challenge for general practice is to optimise the care for these patients. Guidelines are usually configured for individual diseases rather than multimorbidity. Guidelines can only provide structured information and evidence-based recommendations. They are a guide for decision making for individual patients and infrequently address the problems of implementation in different patients with varying personal and clinical priorities.
High-quality management of diabetes cannot occur in isolation from other coexisting physical or mental health disorders, nor can management ignore age and socioeconomic issues.177
Three out of four adults with diabetes have at least one comorbid chronic disease177 and up to 40% have at least three (refer to Figure 6).178,179 These comorbidities may or may not be diabetes related, and awareness and treatment of comorbidities is related to better glycaemic control.180
While many conditions have a concordant treatment focus (eg use of an ACEI to reduce the risk of cardiovascular events), others, such as depression, chronic obstructive pulmonary disease (COPD) and painful conditions may be discordant.181,182 For example, patients may require medications such as NSAIDs that may adversely affect the management of diabetes and whose presence is a risk factor for poorer self care, more frequent diabetes complications and death.183
Age and multimorbidity
Symptomatic conditions may receive priority from patients. Studies of symptomatic burden have found that adults with type 2 diabetes aged ≥60 years report more physical symptoms such as acute pain and dyspnoea, and are more likely to have cognitive impairment and physical disability than those without diabetes.184 Combined with obesity, these risks are approximately doubled. People aged <60 years report more psychosocial symptoms, such as depressed mood and insomnia. Acute pain was prevalent (41.8%) and 39.7% reported chronic pain, 24.6% fatigue, 23.7% neuropathy, 23.5% depression, 24.2% insomnia and 15.6% physical/emotional disability.184
Socioeconomic status and multimorbidity
Being part of the most socially disadvantaged groups in Australia doubles the risk of developing diabetes. Within low socioeconomic groups, financial stressors may also play a role in treatment choices. Hence, the management of diabetes should always be considered as part of a comprehensive management plan, which addresses wholepatient priorities.
Figure 6. Many patients with diabetes have other medical conditions
COPD; chronic obstructive pulmonary disease; TIA; transient ischaemic attack
Reproduced with permission from Elsevier from Barnett K, Mercer SW, Norbury M, et al. Epidemiology of multimorbidity and implications for healthcare, research, and medical education: A cross-sectional study. Lancet 2012;380(9836):37–43.
Approach to multimorbidity
A number of comorbidities are commonly associated with diabetes (refer to Table 12). The best approach for a patient with multimorbidity is the subject of international debate. Unfortunately, multimorbidity increases clinical complexity, which is unlikely to be effectively addressed by more sophisticated guidelines181,185–187 or the Chronic Care Model.188–191 Hence, a set of principles to guide an approach seems to offer a clinical solution.
Table 12. Comorbidities associated with diabetes or arising from complications of diabetes
Chronic pain disorders
Depression and anxiety
Peripheral vascular disease
High-risk foot issues
Renal impairment and chronic kidney disease
Neuropathy – peripheral, autonomic Retinopathy
Low testosterone in males
Joint issues (e.g. frozen shoulder)
Overweight and obesity-related comorbidities
Obstructive sleep apnoea
Bacterial, fungal and viral infections
Consider the following key principles in the approach to management of patients with type 2 diabetes and co-existing morbidities.
Recognise clinical context and prognosis
Consider clinical management decisions within the context of risks, burdens, benefits, and prognosis of a patient’s life (eg remaining life expectancy, functional status, quality of life).181,185,186 Treatment outcomes of glycaemia, hypertension, and hyperlipidaemia all have multi-year time horizons required to provide benefit and these may not be available in all clinical contexts.
Set treatment priorities with the patient
Focus on outcomes that matter most to the individual. Shared decision making with patients is vital to ensure care is aligned with their values and preferences.185,192–195
Even though diabetes may be a clinically dominant condition, patients may prioritise therapeutic interventions differently. For example, pain relief from low back pain or respiratory relief from COPD may be considered above their diabetes needs, many of which may not cause daily symptoms.
Recognise the limitations of the evidence base
Many of the patterns of multimorbidity have similar pathogenesis and therapeutic management strategies (eg diabetes, hypertension, CAD).
Clinical guidance regarding discordant conditions such as steroid-dependent conditions (which potentiate poor glycaemic control), mental health conditions, chronic pain, cancer or conditions that alter medication pharmacokinetics (eg renal disease, cardiac failure, liver disease, malabsorptive states) is often lacking or sparse. The absolute harms and benefits of diabetic medications and burdens are not readily known in these populations. Other unknowns are the realistic estimate of benefit to the patient and treatment horizon (ie the length of time taken for the patient to benefit).185
A degree of clinical judgement and a ‘best care given the circumstances’ is required in these situations.
Polypharmacy (taking >5 medications) is one consequence of following single-disease guidelines in people with multimorbidity.185,196–198
Polypharmacy can be appropriate and has been said to be the price of success in creating effective treatments. It is also associated with higher rates of adverse drug events and hospitalisation, and is often particularly problematic in people who are physically frail189 or have cognitive impairment.
Adherence to therapy can be much more difficult for patients taking numerous medications for multiple conditions.199 Out-of-pocket costs for medication can be significantly higher for patients with diabetes than for most other chronic conditions200 and the financial burden can lead to underuse of preventive services.201,202 Consideration of a home medicine review may assist in some cases.
Use strategies for choosing therapies that optimise benefit, minimise harm and enhance quality of life, particularly in older adults with multimorbidity.
Be aware of common comorbidities with diabetes
Macrovascular disease – includes CAD, hypertension, chronic heart failure, hyperlipidaemia and cerebrovascular disease. CVD is the primary cause of death for many persons with diabetes and is often found in patients with type 2 diabetes (refer to Chapter 9. Managing cardiovascular risk).
Painful conditions (acute and chronic) – are common in patients with type 2 diabetes. Peripheral neuropathies and arthritis account for most causes of pain, as well as tendinopathies.
Arthritis – is particularly problematic as it can reduce self-management capability (eg hand arthritis causing medication administration issues). Arthritis and tendinopathy (and any other cause of pain) can also affect the patient’s ability to engage in physical activity.
Fractures – research has shown that overall fracture risks are significantly higher for men and women with type 2 diabetes. The increased risk of hip fracture has been observed despite patients having higher bone mineral density.
Obstructive sleep apnoea (OSA) – or sleep deprivation from any cause can aggravate insulin resistance, hypertension and hyperglycaemia. OSA is especially common in adults with diabetes (up to 17% of men).203 The usual approach to obstructive sleep apnoea is diagnosis via a sleep study and management with individualised interventions including continuous positive airway pressure. Driver’s licence requirements, particularly in commercial drivers, are particularly relevant.
Cancer – is the second largest cause of death in type 2 diabetes. A growing body of evidence suggests that diabetes and some antidiabetic treatments may increase cancer risk. Patients with diabetes should undergo appropriate cancer screening as recommended for all people in their age and sex. Patients should also try to reduce modifiable cancer risk factors, including quitting smoking, losing weight and increasing physical activity levels.204
Renal impairment – CKD affects approximately 40% of patients with diabetes.
It is both a complication of diabetes and an independent comorbidity present before diabetes onset. The presence of kidney disease worsens CVD risk and limits the number of glucose-lowering medication options available. Further, the availability of over-the-counter nephrotoxic medications (eg NSAIDs) can easily exacerbate disease, and the ‘triple-whammy’ effect (ACEI/diuretic/NSAID) may go unrecognised without specific questioning. The onset of renal disease can be insidious.
Cognitive impairment – has been associated with type 2 diabetes205,206 as well as a higher rates of dementia.207 Recurrent symptomatic and asymptomatic hypoglycaemia have been suggested as possible causal links to this association.
Mental health issues – such as diabetes-related distress, depression and anxiety are common. Rates of depression are increased by 15% in people with diabetes compared with people without diabetes. An Australian study208 using the Patient health questionaire-9 (PHQ-9) scale revealed moderate to severe depressive symptoms in 23% of patients with non-insulin treated type 2 diabetes, rising to 35% in those using insulin, with a proportion of these being undiagnosed. The odds ratio (OR) for depression in patients with type 2 diabetes compared with people without diabetes is higher in males (OR: 1.9; 95% confidence interval [CI]: 1.7–2.1) than females (OR: 1.3; 95% CI: 1.2–1.4).209 Anxiety issues also affect people living with diabetes, and, as with depression, higher rates were seen in women.208
Mental health issues can adversely affect practitioner–patient communication, and the patient’s ability to live and apply the principles of a diabetes management plan and glycaemic control, as well as add to the burden of disease and reduce quality of life. Depression and diabetes are also associated with a significantly increased allcause and CVD-related mortality.
Some antipsychotic medications can increase the risk of developing diabetes. Olanzapine and clozapine are associated with higher rates of diabetes compared with other antipsychotic agents.
Dental problems – such as periodontitis (ie localised inflammation of the supporting structures of the teeth due to a chronic bacterial infection) are more common in patients with diabetes. Periodontitis can result in tooth loss and other dental complications that can interfere with the diet. Additionally, there is a two-way relationship between diabetes and periodontitis – the management of periodontitis may lead to a modest reduction in HbA1c of approximately 0.4%.210–213 Inversely, improving glycaemic control may also improve the severity and complications associated with periodontitis.
Oral and periodontal health reviews should be incorporated into the systematic individualised care of patients with diabetes. Early prevention and intervention may prevent permanent dental loss and help aid in glycaemic control.