Use of capillary blood glucose for screening for gestational diabetes mellitus in resource-constrained settings.
OBJECTIVE
The aim of the study was to evaluate usefulness of capillary blood glucose (CBG) for diagnosis of gestational diabetes mellitus (GDM) in resource-constrained settings where venous plasma glucose (VPG) estimations may be impossible.


METHODS
Consecutive pregnant women (n = 1031) attending antenatal clinics in southern India underwent 75-g oral glucose tolerance test (OGTT). Fasting, 1- and 2-h VPG (AU2700 Beckman, Fullerton, CA) and CBG (One Touch Ultra-II, LifeScan) were simultaneously measured. Sensitivity and specificity were estimated for different CBG cut points using the International Association of Diabetes in Pregnancy Study Groups (IADPSG) criteria for the diagnosis of GDM as gold standard. Bland-Altman plots were drawn to look at the agreement between CBG and VPG. Correlation and regression equation analysis were also derived for CBG values.


RESULTS
Pearson's correlation between VPG and CBG for fasting was r = 0.433 [intraclass correlation coefficient (ICC) = 0.596, p < 0.001], for 1H, it was r = 0.653 (ICC = 0.776, p < 0.001), and for 2H, r = 0.784 (ICC = 0.834, p < 0.001). Comparing a single CBG 2-h cut point of 140 mg/dl (7.8 mmol/l) with the IADPSG criteria, the sensitivity and specificity were 62.3 and 80.7 %, respectively. If CBG cut points of 120 mg/dl (6.6 mmol/l) or 110 mg/dl (6.1 mmol/l) were used, the sensitivity improves to 78.3 and 92.5 %, respectively.


CONCLUSIONS
In settings where VPG estimations are not possible, CBG can be used as an initial screening test for GDM, using lower 2H CBG cut points to maximize the sensitivity. Those who screen positive can be referred to higher centers for definitive testing, using VPG.
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Balaji
B
Bhavadharini
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Manni Mohanraj
MM
Mahalakshmi
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Kumar
K
Maheswari
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Gunasekaran
G
Kalaiyarasi
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Ranjit Mohan
RM
Anjana
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Mohan
M
Deepa
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Harish
H
Ranjani
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Miranda
M
Priya
Seethapathy Clinic and Hospital, Chennai, India.
Ram
R
Uma
Associates in Clinical Endocrinology Education and Research (ACEER), Chennai, India.
Sriram
S
Usha
College of Pharmacy, Purdue University, West Lafayette, IN, USA.
Sonak D
SD
Pastakia
International Diabetes Federation, Brussels, Belgium.
Belma
B
Malanda
International Diabetes Federation, Brussels, Belgium.
Anne
A
Belton
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India.
Ranjit
R
Unnikrishnan
International Diabetes Federation, Brussels, Belgium.
Arivudainambi
A
Kayal
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, WHO Collaborating Centre for Non-communicable Diseases Prevention and Control, IDF Centre of Education, 4, Conran Smith Road, Gopalapuram, Chennai, 600 086, India. drmohans@diabetes.ind.in.
Viswanathan
V
Mohan
D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D002196:Capillaries / Q000737:chemistry*; D016640:Diabetes, Gestational / Q000097:blood / Q000175:diagnosis* / Q000191:economics / Q000453:epidemiology; D005215:Fasting / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test / Q000191:economics / Q000379:methods; D006295:Health Resources / Q000191:economics; D006801:Humans; D007194:India / Q000453:epidemiology; D011203:Poverty / Q000706:statistics & numerical data; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000191:economics / Q000379:methods*; D012680:Sensitivity and Specificity; D055815:Young Adult
D001786:Blood Glucose
Asian Indian; CBG; Capillary blood glucose; Gestational diabetes mellitus; IADPSG criteria; Screening; South Asians; Venous plasma glucose; WHO 1999 criteria