What predicts regression from pre-diabetes to normal glucose regulation following a primary care nurse-delivered dietary intervention? A study protocol for a prospective cohort study

Introduction Pre-diabetes is a high-risk state for the development of type 2 diabetes mellitus (T2DM) and cardiovascular disease. Regression to normoglycaemia, even if transient, significantly reduces the risk of developing T2DM. The primary aim of this mixed-methods study is to determine if there are clinically relevant differences among those with pre-diabetes and excess weight who regress to normoglycaemia, those who have persistent pre-diabetes and those who progress to T2DM following participation in a 6-month primary care nurse-delivered pre-diabetes dietary intervention. Incidence of T2DM at 2 years will be examined. Methods and analysis Four hundred participants with pre-diabetes (New Zealand definition glycated haemoglobin 41–49 mmol/mol) and a body mass index \u3e25 kg/m2 will be recruited through eight primary care practices in Hawke’s Bay, New Zealand. Trained primary care nurses will deliver a 6-month structured dietary intervention, followed by quarterly reviews for 18 months post-intervention. Clinical data, data on lifestyle factors and health-related quality of life (HR-QoL) and blood samples will be collected at baseline, 6 months, 12 months and 24 months. Sixty participants purposefully selected will complete a semi-structured interview following the 6-month intervention. Poisson regression with robust standard errors and clustered by practice will be used to identify predictors of regression or progression at 6 months, and risk factors for developing T2DM at 2 years. Qualitative data will be analysed thematically. Changes in HR-QoL will be described and potential cost savings will be estimated from a funder’s perspective at 2 years. Ethics and dissemination This study was approved by the Northern A Health and Disability Ethics Committee, New Zealand (Ethics Reference: 17/NTA/24). Study results will be presented to participants, published in peer-reviewed journals and presented at relevant conferences. Trial registration number ACTRN12617000591358; Pre-results

The effectiveness of a primary care nursing-led dietary intervention for prediabetes: a mixed methods pilot study

Background Primary care nurse-led prediabetes interventions are seldom reported. We examined the implementation and feasibility of a 6-month multilevel primary care nurse-led prediabetes lifestyle intervention compared with current practice in patients with prediabetes, with weight and glycated haemoglobin (HbA1c) as outcomes. Methods This study used a convergent mixed methods design involving a 6-month pragmatic non-randomised pilot study with a qualitative process evaluation, and was conducted in two neighbouring provincial cities in New Zealand, with indigenous Māori populations comprising 18.2% and 23.0%, respectively. Participants were non-pregnant adults aged ≤ 70 years with newly diagnosed prediabetes (HbA1c 41-49 mmol/mol), body mass index (BMI) ≥ 25 kg/m2 and not prescribed Metformin. A structured dietary intervention tool delivered by primary care nurses with visits at baseline, 2–3 weeks, 3 months and 6 months was implemented in four intervention practices. Four control practices continued to provide usual care. Primary quantitative outcome measures were weight and HbA1c. Linear and quantile regression models were used to compare each outcome between the two groups at follow-up. Qualitative data included: observations of nurse training sessions and steering group meetings; document review; semi-structured interviews with a purposive sample of key informants (n = 17) and intervention patients (n = 20). Thematic analysis was used. Results One hundred fifty-seven patients with prediabetes enrolled (85 intervention, 72 control), 47.8% female and 31.2% Māori. Co-morbidities were common, particularly hypertension (49.7%), dyslipidaemia (40.1%) and gout (15.9%). Baseline and 6 month measures were available for 91% control and 79% intervention participants. After adjustment, the intervention group lost a mean 1.3 kg more than the control group (p  \u3c 0.001). Mean HbA1c, BMI and waist circumference decreased in the intervention group and increased in the control group, but differences were not statistically significant. Implementation fidelity was high, and it was feasible to implement the intervention in busy general practice settings. The intervention was highly acceptable to both patients and key stakeholders, especially primary care nurses. Conclusions Study findings confirm the feasibility and acceptability of primary care nurses providing structured dietary advice to patients with prediabetes in busy general practice settings. The small but potentially beneficial mean weight loss among the intervention group supports further investigation

Additional file 1: of The effectiveness of a primary care nursing-led dietary intervention for prediabetes: a mixed methods pilot study

Prediabetes Intervention Package (PIP) in primary care study process evaluation - key informant and intervention patient interview guides. This file contains copies of the process evaluation interview guide for key informants and the interview guide for intervention participants. (PDF 89 kb