Introduction
Although there are diabetic lifestyle and self-management practices shown to be efficacious for improving glycemic control in clinical trials, these lifestyle changes may be difficult for patients to integrate and maintain in everyday life. Diabetes education can improve self-care, but beneficial effects may wane after a few months, and almost half of US patients with diabetes are not in good glycemic control.1 Identification of successful practices from everyday life may suggest sustainable lifestyle changes. The problem is how to identify strategies and possible adaptations of standard recommendations that are effective in achieving medical management _targets for reducing risk of diabetes complications, but that are acceptable and will be used by patients. Qualitative studies have identified lifestyle behaviors and dietary patterns linked to better glycemic control—behaviors distinctive of those in better glycemic control that may be sustainable due to their occurrence in descriptions of everyday home management of diabetes.2 3 This study validates those results by testing whether the practices are associated with glycemic control in a nationally representative sample of patients with diabetes. Practices identified in a national survey about lifestyle and dietary practices may help to identify sustainable practices.
Successful management of hyperglycemia, hypertension, and dyslipidemia can prevent or delay microvascular and macrovascular complications.4 Each percentage point reduction in hemoglobin A1c (HbA1c) (eg, from 9.0 to 8.0 (75–64 mmol/mol)) can result in 35% fewer microvascular complications and 25% fewer diabetes-related deaths.5 Evidence indicates that weight loss, increased physical activity, and self-monitoring of blood glucose (SMBG) can reduce hyperglycemia.6–10 However, a one-size-fits-all approach to lifestyle and management may not be necessary or beneficial to patients.11 Newly diagnosed patients who achieve tighter glycemic control may reduce or delay cardiovascular, renal, visual, and neurological complications and even mortality,12 while older patients with long-standing disease may not benefit from tight glycemic control.13–16 Although SMBG, weight loss, and physical activity are efficacious in clinical trials in reducing hyperglycemia (HbA1c), their effectiveness diminishes over time and in less-controlled settings. Prevention or delay of diabetic complications requires patient and provider communication and cooperation, with patient adherence to lifestyle changes. Unfortunately, clinical support for these changes may be limited to encouragement. The result is that lifestyle changes may not be sustained in the daily lives of patients, resulting in poorer glycemic control.1 17
Two recent qualitative studies (one in the USA2 and one in Mexico3) explored the lifestyle practices of patients with type 2 diabetes to identify successful strategies used by patients in good control. In contrast to most qualitative studies that have not systematically compared those in good control with those in poor control,18–21 these two studies used a case–control design comparing patients with good and poor control matched across groups for duration of diabetes and treatment modality (oral or insulin treatment). This matched-pairs design controlled for factors not under patient control but that are associated with glycemia, in order to identify successful strategies and lifestyle practices. In both studies, clinic patients were interviewed and most had limited physical activity (many had physical disabilities) and instead used a variety of dietary strategies to manage their diabetes. For example, practices such as ‘avoid eating sweets’ were reported by both good and poor glycemic control patients, while ‘drinking non-caloric beverages to avoid eating more food’ was distinctive of patients in good control. In the US study, patients in good control tested their glucose more frequently, monitored dietary sodium, increased their intake of fruits and vegetables, limited portion sizes, and used memory aids to remember to take medications. Similar dietary strategies were identified in both the US and Mexico studies and suggest that these strategies may be useful more broadly in maintaining glycemic control.
The qualitative studies raised a very interesting issue: namely, how are patients in good control actually manage their diabetes and can these practices be validated and possibly disseminated to others? This study is the first step in that process, namely a validation of the strategies from the qualitative studies that were linked to better glycemic control. The qualitative results suggested lifestyle strategies that might be acceptable to patients and might be effective for maintaining good glycemic control. A strength of qualitative studies is their ability to generate and explore new ideas, but it is difficult to evaluate and generalize results from such studies due to the small, non-representative samples. In this study, themes and practices identified in the qualitative studies were matched to questions in the US National Health and Nutrition Examination Survey (NHANES) and responses were compared with glycemic control. The NHANES contains data on diabetes and dietary practices based on a nationally representative sample to monitor US health status and is also used to estimate the prevalence and general health of patients with diabetes.1 17 Thus, this study validates the lifestyle practices identified in qualitative studies by testing whether those practices are associated with good control in a large, nationally representative sample. Future intervention studies might then test for the sustainability of those practices.