Learning outcomes
After reading this chapter, you should be able to:
• describe cardiovascular disease (CVD), insulin resistance, and type 2 diabetes (T2D)
• describe the human cardiovascular system, the pancreas, the role of insulin and the metabolism of carbohydrates
• identify common causes of CVD and T2D
• explain the medical regimen for someone with T2D
• describe treatment and prevention strategies for CVD and T2D
• evaluate the interconnection between CVD, T2D and depression, how depression complicates CVD and T2D and suggest possible treatment regimens for lifestyle-related chronic illnesses and comorbid depression.
Introduction
Chronic illness, depression and lifestyle behaviours are strongly interrelated. Chronic illness, for the purposes of this chapter, will only refer to the lifestyle-related chronic illnesses (LRCI), namely type 2 diabetes (T2D) and cardiovascular disease (CVD), conditions strongly determined by lifestyle behaviours. There is well-established evidence that a diet lacking in nutrition and a lack of physical activity contribute to both illnesses (AIHW, 2014a). Moreover, both are associated with an increased risk of depression (National Heart Foundation of Australia [NHFA], 2013; Peyrot & Rubin, 1997).
The rate of depression associated with CVD or T2D is two to three times the rate found in the general population (Anderson et al., 2001; Musselman, Evans & Nemeroff, 1998), which is about 4.1 to 14.5% (ABS, 2008). Conversely, there is also well-established evidence that depression increases the risk for these illnesses, particularly CVD. Depression is also associated with an increase in unhealthy lifestyle behaviours, particularly inactivity, and conversely, unhealthy lifestyle behaviours can increase the risk for depression. These interrelated relationships are depicted in Figure 9.1.
This chapter will introduce you to CVD and T2D. The chapter begins with an overview of CVD and the human cardiovascular system. This will be followed by an introduction to the main types of CVD that are related to lifestyle behaviours, and includes a description of atherosclerosis, the leading underlying physiological cause of CVD. An introduction to T2D will follow, with a discussion of its precursor, insulin resistance. In this section the role of the pancreas, insulin and glucose metabolism will be briefly outlined.