Glycaemic streaming in type 1 diabetes: implications for intervention?

Abstract

Evidence exists that mean glycaemia in individuals with type 1 diabetes may remain remarkably constant (glycaemic ‘streaming’ or ‘tracking’). We have re‐examined this in a group of type 1 patients, to explore whether any subgroups may be more or less amenable to glycaemic improvement.We made a retrospective analysis between 2003 and 2007 of 181 people with type 1 diabetes. Basic demographic information, and sequential glycated haemoglobin (HbA1c) levels during the five‐year follow‐up period (2003–2007), were recorded. First (2003) and last HbA1c levels were recorded, and mean HbA1c for the whole period. These were analysed as a total group, by gender, and by glycaemic control (initial HbA1c over or below 64mmol/mol [8.0%]).Mean age was 41±8 years, diabetes duration 19±9 years, 58% were male, and mean HbA1c was 75±17mmol/mol (9.0±1.6%). Over the study period there was a small improvement in total population mean HbA1c (75±17 to 72±16mmol/mol [9.0±1.6 to 8.7±1.5%], p=0.003). This was accounted for by improvements in male (74±17 to 70±15mmol/mol [8.9±1.6 to 8.6±1.4%], p=0.005) and poorly‐controlled (HbA1c ≥65mmol/mol [8.1%]) patients (79±15 to 75±15mmol/mol [9.4±1.4 to 9.0±1.4%], p=0.002). Female and well‐controlled (HbA1c ≤64mmol/mol [8.0%]) patients showed no change in mean glycaemia.Most patients maintained closely similar HbA1c levels over time. Interventions in type 1 diabetes may be more usefully aimed at risk factors rather than glycaemia. Copyright © 2013 John Wiley & Sons.

Clinically meaningful and lasting HbA1c improvement rarely occurs after 5 years of type 1 diabetes: an argument for early, targeted and aggressive intervention following diagnosis

“…Second, the benefits of addressing HbA 1c after the first 5 years should be explored. It has been suggested that efforts would be better directed at risk factors other than HbA 1c in individuals with established type 1 diabetes [13]. However, such an approach may result in loss of the tracking phenomenon and deterioration in HbA 1c so this needs to be carefully explored.…”

“…Crucially, previous reports [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] have largely examined individuals with pre-existing type 1 diabetes (i.e. not from the time of diagnosis).…”

Characteristics of newly diagnosed adults with type 1 diabetes in the UK and evolution of glycaemic control, body mass index and Charlson comorbidity index over the first 5 years after diagnosis

“…In the first year following treatment with insulin, there were significant improvements in glycaemic control, with a mean (SD) HbA 1c of 61 (21.9) mmol/mol [7.7 (2.0) %] accompanied by significant increases in BMI, with no further improvement in the years thereafter. Other work has also reported that glycaemic control tends to remain constant (glycaemic streaming), emphasising the importance of maximising gains soon after diagnosis [9]. Conversely, the lack of further improvement in glycaemic control in years 2-5 in this study was consistent with findings from the National Diabetes Audit, which indicated that less than one-third of the population with T1D achieved glycaemic target of <58 mmol/mol (<7.5%) in 2016/2017 [10].…”

Use of clinical targets in diabetes patient education: qualitative analysis of the expectations and impact of a structured self‐management programme in Type 1 diabetes

“…These have consistently shown that DAFNE students have much lower rates of severe hypoglycaemia than the DCCT cohort, yet almost always manage to make significant reductions in average HbA 1c (Fig. 1) [5][6][7][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Yet, although students on DAFNE are asked to aim for a target of 45-55 mmol/mol (6.0-7.0%), they in fact attain a mean HbA 1c concentration of~68 mmol/mol [~8.4% (Fig 1)].…”