Persistent C-peptide is associated with reduced hypoglycaemia but not HbA1c in adults with longstanding Type 1 diabetes: evidence for lack of intensive treatment in UK clinical practice?

AIMS

Most people with Type 1 diabetes have low levels of persistent endogenous insulin production. The Diabetes Control and Complications Trial showed that close to diagnosis preserved endogenous insulin was associated with lower HbA_1c , hypoglycaemia and complication rates, when intensively treated. We aimed to assess the clinical impact of persistent C-peptide on rate of hypoglycaemia and HbA_1c in those with long duration (> 5 years) Type 1 diabetes.

METHODS

We conducted a cross-sectional case-control study of 221 people (median age 24 years) with Type 1 diabetes. We confirmed ongoing endogenous insulin secretion by measuring C-peptide after a mixed-meal tolerance test. We compared self-reported hypoglycaemia (n = 160), HbA_1c , insulin dose and microvascular complications (n = 140) in those with preserved and low C-peptide.

RESULTS

Stimulated median (IQR) C-peptide was 114 (43, 273) pmol/l and < 3 (< 3, < 3) pmol/l in those with preserved and low C-peptide respectively. Participants with preserved C-peptide had lower reported monthly rates of hypoglycaemia, with 21% fewer symptomatic episodes, 5.9 vs. 7.5 [incidence rate ratio (IRR) 0.79, P = 0.001], and 65% fewer asymptomatic episodes, 1.0 vs. 2.9 (IRR 0.35, P < 0.001). Those with preserved C-peptide had a lower insulin dose (0.68 vs. 0.81 units/kg, P = 0.01) but similar HbA_1c (preserved 69 vs. low 67 mmol/mol, P = 0.06).

CONCLUSIONS

Adults with Type 1 diabetes and preserved endogenous insulin production receiving usual care in the UK have lower daily insulin doses and fewer self-reported hypoglycaemic episodes, but no difference in HbA_1c . This is consistent with non-intensive treatment in previous studies, and suggests a need to consider therapy intensification to gain full benefit of preserved endogenous insulin.

Short-term effects of severe dietary carbohydrate-restriction advice in Type 2 diabetes--a randomized controlled trial

OBJECTIVE

This study sought to examine the effects of a 3-month programme of dietary advice to restrict carbohydrate intake compared with reduced-portion, low-fat advice in obese subjects with poorly controlled Type 2 diabetes.

RESEARCH DESIGN AND METHODS

One hundred and two patients with Type 2 diabetes were recruited across three centres and randomly allocated to receive group education and individual dietary advice. Weight, glycaemic control, lipids and blood pressure were assessed at baseline and 3 months. Dietary quality was assessed at the end of study.

RESULTS

Weight loss was greater in the low-carbohydrate (LC) group (-3.55 +/- 0.63, mean +/- sem) vs. -0.92 +/- 0.40 kg, P = 0.001) and cholesterol : high-density lipoprotein (HDL) ratio improved (-0.48 +/- 0.11 vs. -0.10 +/- 0.10, P = 0.01). However, relative saturated fat intake was greater (13.9 +/- 0.71 vs. 11.0 +/- 0.47% of dietary intake, P < 0.001), although absolute intakes were moderate.

CONCLUSIONS

Carbohydrate restriction was an effective method of achieving short-term weight loss compared with standard advice, but this was at the expense of an increase in relative saturated fat intake.

Screening for diabetic retinopathy is well received by patients and may improve self-management intentions

AIMS

To investigate patients' views of screening for diabetic retinopathy and the effects of the screening process on health beliefs and behavioural intentions.

SETTING

A retinal screening clinic at a GP surgery in SW England.

METHODS

Questionnaires administered before and immediately after screening by retinal photography.

RESULTS

One hundred patients attended (94% of those invited); 12 had Type 1 and 88 Type 2 diabetes. Over 90% found the information, and seeing their retinal photograph, helpful. Sixty-three were found to have no problem and 37 had some type of eye problem detected. Overall, patients rated the news given at screening as better than expected (P < 0.001) and even those found to have problems mostly rated the news as good (P < 0.001). Detection of problems led patients to rate their recent eye health more negatively, but to be less pessimistic about future deterioration (P < 0.01). Patients with diabetes-related eye problems were more likely (P < 0.05) to say that they both should and would make changes to their self-management, but only after controlling for duration of diabetes. Those who had had diabetes longest declared least intention to change.

CONCLUSIONS

Screening by retinal photography is acceptable to patients. Results suggest that screening modified health beliefs but had limited effect on behavioural intentions, with patients of longer disease duration being more reluctant to change their self-management. Opportunities during retinal screening for advice on self-management could be more effectively exploited.