LIFESTYLE RISK FACTORS FOR TYPE 2 DIABETES

In recent decades, changes in people's behaviour and lifestyle due to the modernisation of society and shifts to diets containing more energy-dense foods have resulted in escalating rates of both obesity and Type 2 diabetes (the clinical association of which is popularly becoming known as 'diabesity') [9].

Nine out of ten people with diabetes around the world have Type 2 diabetes [1]. While some people may be at a higher risk of developing diabetes due to genetic factors, this condition is largely preventable as many of the risk factors for developing the disease, such as excess weight, poor diet, inactivity, smoking, and excessive consumption of alcohol, are modifiable behaviours. Although there is currently no cure for Type 2 diabetes, it can often initially be managed with healthy eating and regular physical activity [10].

Due to the relatively small number of persons under 35 years with Type 2 diabetes, this section focuses on selected body mass index (BMI), physical activity and nutrition characteristics of people aged 35 years and over, with and without Type 2 diabetes. All rates comparing people with and without Type 2 diabetes in this section are age standardised.

EXCESS WEIGHT

In 2007-08, after adjusting for age, obese men were twice as likely to have Type 2 diabetes (12%) as men who were overweight (6%) or in the underweight/normal weight range (5%). While rates were lower, obese women were also twice as likely to have Type 2 diabetes (8%) as women who were overweight (4%) or in the underweight/normal weight range (3%).

People with Type 2 diabetes were almost twice as likely to be obese as people without Type 2 diabetes (51% and 27% respectively).

PHYSICAL ACTIVITY

Participation in regular moderate to vigorous physical activity can help prevent the onset of a range of diseases including diabetes. For adults, the National Physical Activity Guidelines recommend at least 30 minutes of moderate-intensity physical activity on most, preferably all, days of the week [11].

2007-08 data shows that men who exercised at high or moderate levels were less likely to have Type 2 diabetes (6%) than those who were sedentary or exercised at low levels (8%), although the difference for women who exercised at high or moderate levels and those who were sedentary or exercised at low levels was not statistically significant.

Around 80% of people with Type 2 diabetes were sedentary or exercised at low levels, compared with 74% of people without the condition. People without Type 2 diabetes were more likely to exercise at high or moderate levels (Graph 3).




NUTRITION

A healthy diet can boost the immune system and prevent a range of chronic diseases associated with obesity such as Type 2 diabetes. The National Health and Medical Research Council (NHMRC) recommends that adults consume at least two serves of fruit and five serves of vegetables per day [12].

People with Type 2 diabetes were just as likely to eat the recommended daily serves of fruit and vegetables as people without the condition. They were more likely, however, to have increased their fruit (24%) and vegetable (23%) consumption in the past year than people without Type 2 diabetes (9% and 11% respectively) (Graph 4), which may reflect shifts in self-management of their condition. Three quarters of people with diabetes actively changed their diets to manage their condition (see Section 4 - Managing the Risks for more detail).




SMOKING

Smoking can increase the risk of developing diabetes-related complications such as coronary heart disease, stroke, peripheral vascular disease and kidney disease. Research shows that quitting smoking can reduce the risk of developing Type 2 diabetes [13]. In 2007-08, around 8% of people aged 35 years and over that had ever smoked had Type 2 diabetes compared with 6% of those who had never smoked.

After adjusting for age, the smoking and ex-smoking rates of people with Type 2 diabetes aged 35 years and over were not significantly different to those of people without the condition. Smokers with Type 2 diabetes were also no more likely to have increased or decreased their smoking over the past 12 months than smokers without Type 2 diabetes.

ALCOHOL

Alcohol can impair the liver's ability to produce glucose [14] resulting in hypoglycaemia (low blood glucose), which if untreated can cause anxiety, palpitations, changes in behaviour, coma, and seizures [15]. Excessive consumption of alcohol can also cause hypoglycaemia if people are taking insulin or certain diabetes medications, and increases the risk of developing complications through weight gain and increasing blood pressure [16]. The 2001 National Health and Medical Research Council (NHMRC) guidelines for reducing health risks in the longer term from alcohol limit consumption to four standard drinks a day for men and two standard drinks a day for women [17].

In 2007-08, there was no significant difference between rates of risky or high risk drinking for people with or without Type 2 diabetes. A higher proportion of people with Type 2 diabetes last consumed alcohol 12 or more months ago (16%) compared with people without Type 2 diabetes (6%). They were also more likely to have last consumed alcohol more than one week ago but less than 12 months ago. Of people 35 years and over who had never consumed alcohol, 10% had Type 2 diabetes, while only 4% of risky or high risk drinkers the same age had the condition.