The accuracy of haemoglobin A1c as a screening and diagnostic test for gestational diabetes: a systematic review and meta-analysis of test accuracy studies

PURPOSE OF REVIEW: Gestational diabetes mellitus (GDM) is associated with adverse pregnancy complications. Accurate screening and diagnosis of gestational diabetes are critical to treatment, and in a pandemic scenario like coronavirus disease 2019 needing a simple test that minimises prolonged hospital stay. We undertook a meta-analysis on the screening and diagnostic accuracy of the haemoglobin A1c (HbA1c) test in women with and without risk factors for gestational diabetes. RECENT FINDINGS: Unlike the oral glucose tolerance test, the HbA1c test is simple, quick and more acceptable. There is a growing body of evidence on the accuracy of HbA1c as a screening and diagnostic test for GDM. We searched Medline, Embase and Cochrane Library and selected relevant studies. Accuracy data for different thresholds within the final 23 included studies (16 921 women) were pooled using a multiple thresholds model. Summary accuracy indices were estimated by selecting an optimal threshold that optimises either sensitivity or specificity according to different scenarios. SUMMARY: HbA1c is more useful as a specific test at a cut-off of 5.7% (39 mmol/mol) with a false positive rate of 10%, but should be supplemented by a more sensitive test to detect women with GDM

Metformin in the prevention of type 2 diabetes after gestational diabetes in postnatal women (OMAhA): A UK multicentre randomised, placebo-controlled, double-blind feasibility trial with nested qualitative study

OBJECTIVE: To determine the feasibility of a definitive trial of metformin to prevent type 2 diabetes in the postnatal period in women with gestational diabetes. DESIGN: To determine the feasibility of a definitive trial of metformin to prevent type 2 diabetes in the postnatal period in women with gestational diabetes. SETTING: Three inner-city UK National Health Service hospitals in London. PARTICIPANTS: Pregnant women with gestational diabetes treated with medication. INTERVENTIONS: 2 g of metformin (intervention) or placebo (control) from delivery until 1 year postnatally. PRIMARY OUTCOME MEASURES: Rates of recruitment, randomisation, follow-up, attrition and adherence to the intervention. SECONDARY OUTCOME MEASURES: Preliminary estimates of glycaemic effects, qualitative exploration, acceptability of the intervention and costs. RESULTS: Out of 302 eligible women, 57.9% (175/302) were recruited. We randomised 82.3% (144/175) of those recruited, with 71 women in the metformin group and 73 women in the placebo group. Of the participants remaining in the study and providing any adherence information, 54.1% (59/109) took at least 75% of the target intervention dose; the overall mean adherence was 64% (SD 33.6). Study procedures were found to be acceptable to women and healthcare professionals. An increased perceived risk of developing type 2 diabetes, or a positive experience of taking metformin during pregnancy, encouraged participation and adherence to the intervention. Barriers to adherence included disruption to the medication schedule caused by the washout periods ahead of each study visit or having insufficient daily reminders. CONCLUSIONS: It is feasible to run a full-scale definitive trial on the effectiveness of metformin to prevent type 2 diabetes in women with gestational diabetes, during the early postnatal period. Adherence and engagement with the study could be improved with more regular reminders and potentially the addition of ongoing educational or peer support to reinforce messages around type 2 diabetes prevention

Acceptability and adherence to a Mediterranean diet in the postnatal period to prevent type 2 diabetes in women with gestational diabetes in the UK: a protocol for a single-arm feasibility study (MERIT)

Introduction: Women with gestational diabetes are at increased risk of developing type 2 diabetes later in life. In at-risk general populations, Mediterranean-style diet helps prevent type 2 diabetes. But its effect on postnatal women with a history of gestational diabetes is not known. Prior to a full-scale trial on Mediterranean-style diet in the postnatal period to prevent type 2 diabetes, a feasibility study is required to assess the acceptability of the diet and evaluate the trial processes. Methods and analysis: MEditerranean diet for pReventIon of type 2 diabeTes is a single-arm feasibility study (65 women) with qualitative evaluation of women who have recently given birth and had gestational diabetes. The intervention is a Mediterranean-style diet supplemented with nuts and olive oil, with dietary advice and an action plan. A dedicated Health Coach will interact with participants through an interactive lifestyle App. Women will follow the intervention from 6 to 13 weeks post partum until 1 year post partum. The primary outcomes are rates of recruitment, follow-up, adherence and attrition. The secondary outcomes are maternal dysglycaemia, cost and quality of life outcomes, and acceptability of the intervention to participants, and to healthcare professionals delivering the intervention. Feasibility outcomes will be reported using descriptive statistics. Ethics and dissemination: Ethical approval was obtained through the South Central—Berkshire Research Ethics Committee (19/SC/0064). Study findings will be disseminated via publication in peer-reviewed journals, as well as via newsletters made available to participants and members of Katie’s Team (a women’s health patient and public advisory group). Trial registration number: ISRCTN40582975

The Endocrine and Metabolic Characteristics of a Large Bardet-Biedl Syndrome Clinic Population

Context: Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder in which previous reports have described obesity and a metabolic syndrome. Objective: We describe the endocrine and metabolic characteristics of a large BBS population compared with matched control subjects. Design: We performed a case-control study. Setting: This study was performed at a hospital clinic. Patients: Study patients had a clinical or genetic diagnosis of BBS. Main Outcome Measurements: Our study determined the prevalence of a metabolic syndrome in our cohort. Results: A total of 152 subjects were studied. Eighty-four (55.3%) were male. Mean (± standard deviation) age was 33.2 ± 1.0 years. Compared with age-, sex-, and body mass index-matched control subjects, fasting glucose and insulin levels were significantly higher in subjects with BBS (glucose: BBS, 5.2 ± 1.2 mmol/L vs control, 4.9 ± 0.9 mmol/L, P = 0.04; insulin: BBS, 24.2 ± 17.0 pmol/L vs control, 14.2 ± 14.8 pmol/L, P < 0.001). Serum triglycerides were significantly higher in subjects with BBS (2.0 ± 1.2 mmol/L) compared with control subjects (1.3 ± 0.8 mmol/L; P < 0.001), but total cholesterol, high-density lipoprotein, and low-density lipoprotein were similar in both groups. Systolic blood pressure was higher in the BBS group (BBS, 135 ± 18 mm Hg vs control subjects, 129 ± 16 mm Hg; P = 0.02). Alanine transaminase was raised in 34 (26.8%) subjects with BBS, compared with five (8.9%) control subjects (P = 0.01). The rate of metabolic syndrome, determined using International Diabetes Federation criteria, was significantly higher in the BBS group (54.3%) compared with control subjects (26% P < 0.001). Twenty-six (19.5%) of male subjects with BBS were hypogonadal (serum testosterone, 9.9 ± 5.3 mmol/L), but significant pituitary abnormalities were uncommon. Subclinical hypothyroidism was present in 24 of 125 (19.4%) patients with BBS, compared with 3 of 65 (4.6%) control subjects (P = 0.01). Conclusions: Insulin resistance and the metabolic syndrome are increased in adult patients with BBS compared with matched control subjects. Increased subclinical hypothyroidism in the BBS cohort needs further investigation

The endocrine and metabolic characteristics of a large Bardet-Biedl syndrome clinic population

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder in which previous reports have described obesity and a metabolic syndrome.Describe the endocrine and metabolic characteristics of a large BBS population compared with matched controls.Case-control.Hospital clinic.A clinical/genetic diagnosis of BBS.None.Prevalence of metabolic syndrome.One hundred and fifty-two subjects were studied. Eight-four (55.3%) were male and mean (±SD) age was 33.2±1.0 years. Compared with age, gender and BMI matched controls, fasting glucose and insulin levels were significantly higher in BBS subjects (glucose: BBS: 5.2±1.2mmol/l vs control 4.9±0.9mmol/l, p=0.04; insulin: BBS: 24.2±17.0pmol/l vs control 14.2±14.8pmol/l, p<0.001). Serum triglycerides were significantly higher in BBS subjects (2.0±1.2mmol/l) compared with controls (1.3± 0.8mmol/l p<0.001) but total cholesterol/HDL/LDL were similar in both groups. Systolic blood pressure was higher in the BBS group (BBS 135±18 mmHg vs controls 129±16mmHg (p=0.02). Alanine transaminase (ALT) was raised in 34 (26.8%) BBS subjects, compared to 5 (8.9%) controls (p=0.01). The presence of a metabolic syndrome, using IDF criteria, was significantly higher in the BBS group (54.3%) compared to controls (26% p<0.001). Twenty-six (19.5%) of BBS males were hypogonadal (serum testosterone 9.9±5.3 mmol/l) but significant pituitary abnormalities were uncommon. Subclinical hypothyroidism was present in 24/125 (19.4%) patients with BBS compared with 3/65 (4.6%) controls (p=0.01).Insulin resistance and the metabolic syndrome are increased in adult BBS compared with matched controls. Increased subclinical hypothyroidism in the BBS cohort is a novel finding that needs further investigation