Preventing Type 2 Diabetes: Perceptions about risk and prevention in a population-based sample of adults ≥45 years of age

Type 2 diabetes is increasing in the U.S. and constitutes a major public health problem (1). Preventing the onset of diabetes through lifestyle changes, such as improved diet, increased physical activity, and weight control, in individuals at risk presents an attractive public health opportunity. Recently, a randomized controlled clinical trial from Finland showed a 58% decrease in the incidence of type 2 diabetes when lifestyle interventions were conducted in high-risk subjects (2). Similar studies comparing lifestyle interventions and pharmacological therapies to prevent type 2 diabetes are currently underway (3). However, implementing diabetes prevention interventions in the general population will be challenging.

From November 2000 through January 2001, the Montana Department of Public Health and Human Services conducted a random-digit household telephone survey of people ≥45 years of age living in two rural counties in Montana. Respondents were asked if they had ever been told by a physician that they had diabetes (including gestational diabetes), if they had a family history of diabetes (sister, brother, or parents), and if they had ever been told they had high cholesterol and/or high blood pressure. Respondents with a previous diagnosis of diabetes (except gestational diabetes) were excluded. The remaining respondents were asked, “Do you think you are at risk for diabetes?,” “Do you think that you can prevent getting diabetes?,” and “Has a doctor or other health professional ever told you that you may be at risk for developing diabetes?” BMI was calculated based on self-reported height and weight. Respondents with a BMI ≥25.0 were defined as overweight, and respondents with a BMI ≥30.0 were defined as obese. Risk factors, including age ≥45 years, family history of diabetes, history of gestational diabetes, being overweight, history of high blood pressure, and history of high cholesterol, were categorized for each respondent. Hypertension and a history of high cholesterol were used to indicate a possible association with the insulin resistance/metabolic syndrome. Pearson’s χ² tests were used to assess associations among perceived risk for diabetes, perceived ability to prevent diabetes, and medical advice regarding diabetes risk. Logistic regression analyses were conducted to identify independent variables associated with these responses. Odds ratios (ORs) and 95% CIs were calculated.

A total of 605 people were reached by telephone, and 29 (4.8%) of these reported that they had diagnosed diabetes and were excluded from the analyses. Of the total respondents, 571 (94.4%) reported that they did not currently have diabetes. In addition, five (0.8%) women reported a history of gestational diabetes only and were included in the analyses. Among those with no current diagnosis of diabetes, the majority of respondents were female (60%) and the mean age was 60 years (maximum age 97 years). Altogether, 38% reported a family history of diabetes, 49% had a BMI ≥25.0, 26% reported having high blood pressure, and 28% reported having high cholesterol.

Also, 22% of the respondents considered themselves at risk for diabetes, 71% did not consider themselves at risk, and 7% were unsure; 60% thought they could prevent diabetes, 17% did not, and 23% were unsure. Only 10% of the respondents reported receiving medical advice regarding diabetes risk.

The probability of considering oneself at risk for diabetes was higher among respondents who were 45–64 years of age, female, and obese and who had high blood pressure and a family history of diabetes (Table 1). People aged 45–64 years were also more likely than older respondents to feel that they could prevent diabetes. Those with high blood pressure, high cholesterol, and a family history of diabetes were less likely to feel that they could prevent diabetes. Women, obese respondents, those with high blood pressure, and those with a family history of diabetes were more likely than others to have received medical advice from a health professional regarding diabetes risk.

Including age ≥45 years as a risk factor, 20% of respondents had one factor suggesting high risk for diabetes, 37% had two factors, and 43% had three to six factors. Although people with three or more factors were more likely than people with fewer than three risk factors to consider themselves at risk for diabetes (P < 0.001), people with three or more risk factors were less likely to feel that they could prevent diabetes (P = 0.002) (Table 1). However, respondents with three or more risk factors were more likely than those with fewer risk factors to recall having received medical advice from a health care professional regarding diabetes risk (P < 0.001).

After adjusting for multiple factors, younger age (OR 2.59 [95% CI 1.51–4.46]), high blood pressure (1.93 [1.16–3.23]), family history of diabetes (6.65 [4.17–10.61]), and being overweight (3.81 [2.34–6.20]) were independently associated with respondents considering themselves at risk for diabetes. Men were less likely than women to consider themselves at risk (0.53 [0.33–0.87]). Respondents with high blood pressure (0.80 [0.35–0.79]), high cholesterol (0.52 [0.34–0.78]), and a family history of diabetes (0.65 [0.45–0.93]) were less likely to feel they could prevent diabetes. Those with a family history of diabetes (6.42 [3.27–12.62]) and those who were overweight (2.28 [1.22–4.29]) were more likely to report having received medical advice regarding diabetes risk. Men, however, were less likely than women to recall medical advice regarding diabetes risk (0.46 [0.23–0.90]).

People must perceive that they are at risk for type 2 diabetes and believe that diabetes can be prevented before they will initiate and maintain positive diet and exercise behaviors or prophylactic medication. In this survey, people reporting multiple risk factors for diabetes were less likely to perceive that diabetes was preventable than those with fewer risk factors. Although a family history of diabetes was most strongly associated with an individual’s perceived risk, those with a positive family history were less likely than others to believe that diabetes was preventable. Of particular interest is the finding that few respondents reported receiving medical advice from health professionals regarding diabetes risk. It is likely that more respondents in our study were at risk for diabetes than those who could recall receiving medical advice concerning their personal risk for diabetes. Although this study was conducted in two predominantly white, western, U.S. rural counties and has the limitations inherent in any telephone survey, the data have important implications. Our study suggests that widespread translation of the findings of type 2 diabetes prevention trials will require changing the beliefs about primary prevention in those at the highest risk for diabetes and aggressively promoting diabetes prevention in medical practice.