Saravanan, Ponnusamy

Saravanan, Ponnusamy

Biography

Professor Saravanan is a Professor and Honorary Consultant Physician in Diabetes, Endocrinology & Metabolism at Warwick Medical School, University of Warwick & George Eliot Hospital, Nuneaton. He is the Lead for Diabetes division for the NIHR Clinical Research Network, West Midlands. He is the Founder-Director of international Doctoral Training Programme, which focusses on research capacity building activities in low- and middle-income countries. He splits his time equally between clinical and research activity. For the past 17 years, Prof Saravanan’s main research focus is understanding the mechanisms and ethnic variations in ‘programming of obesity and cardiometabolic disorders’ as well as ‘precision medicine’. He has published >130 peer reviewed articles and won several national and international awards. He passionately believes in 'primordial prevention' of metabolic disorders and approaches this by focusing on the health of young women and Gestational Diabetes (GDM). To address this, he has set up early pregnancy cohorts across the world (UK – PRiDE study, n=4746; STRiDE – India, n=3070; STRiDE – Kenya, n= 4134; Malaysia – MAGIC, n=5200 and Thailand – TaRGET, n=4260). His team won the prestigious NHS Innovation award in 2015 for individualised diabetes management for South Asians in the UK. He is instrumental in fast-track adoption of newer therapies and technologies in diabetes locally, regionally, and nationally. During the Covid-19 pandemic he was instrumental in writing the new RCOG UK screening guidelines for GDM based on his work, which was adopted widely in the UK. He co-led the BABYSTEPS trial – an innovative, combined face-face and remote intervention in post-GDM women to improve their physical activity, in collaboration with University of Leicester. He is the Editor-in-Chief for the RCP’s journal, Clinical Medicine. He reviews grants and board member for funding bodies nationally and internationally.

Publication Search Results

Now showing 1 - 10 of 47

Prevalence of vitamin B-12 insufficiency during pregnancy and its effect on offspring birth weight : a systematic review and meta-analysis
(Oxford University Press / USA, 2016-05) Sukumar, Nithya; Rafnsson, Snorri B.; Kandala, Ngianga-Bakwin; Bhopal, Raj; Yajnik, Chittaranjan S.; Saravanan, Ponnusamy; University of Warwick; University College London; University of Edinburgh; Northumbria University, Newcastle upon Tyne; Luxembourg Institute of Health; King Edward Memorial Hospital and Research Centre, Pune, India; George Eliot Hospital, Nuneaton; Diabetes and Endocrinology; Medical and Dental; Saravanan, Ponnusamy
Background: Vitamin B-12 and folate are micronutrients essential for normal embryogenesis. Vitamin B-12 insufficiency in pregnancy is high in certain parts of the world, such as India, and although this has been linked to low birth weight (LBW) in these populations, the relation between vitamin B-12 and birth weight (BW) elsewhere is unknown. Objectives: We performed a systematic review to assess 1) the worldwide prevalence of vitamin B-12 insufficiency in pregnancy and 2) its association with BW. Design: A search of 5 electronic databases was performed to identify eligible articles. Random-effects meta-analysis was conducted according to geographic regions and pregnancy trimesters for the prevalence subreview and by categorical measures of BW. Results: A total of 57 and 23 articles were included for the prevalence and BW subreviews, respectively. The pooled estimates of vitamin B-12 insufficiency were 21%, 19%, and 29% in the first, second, and third trimesters, respectively, with high rates for the Indian subcontinent and the Eastern Mediterranean. The large heterogeneity between studies was partially addressed by creating a standardized score for each study (mean vitamin B-12 insufficiency ÷ cutoff value), which internally corrected for geographic region, trimester, and assay type. Twelve of the 13 longitudinal studies included showed a decrease in mean or median vitamin B-12 across trimesters. Pooled analysis showed nonsignificantly lower maternal vitamin B-12 concentrations in LBW than in normal-BW infants and higher odds of LBW with lower vitamin B-12 values (adjusted OR: 1.70; 95% CI: 1.16, 2.50), but studies from India largely contributed to the latter. Conclusions: Our review indicates that vitamin B-12 insufficiency during pregnancy is common even in nonvegetarian populations and that concentrations of vitamin B-12 decrease from the first to the third trimester. There is no consistent association between vitamin B-12 insufficiency and LBW. However, given the long-term risks of LBW, this observation warrants further cohort studies and randomized controlled trials.
Postnatal testing following gestational diabetes – Authors' reply
(Elsevier, 2015-10) Venkataraman, Hema; Sattar, Naveed; Saravanan, Ponnusamy; University of Warwick; University of Glasgow; George Eliot NHS Trust, Nuneaton; Diabetes and Endocrinology; Medical and Dental; Saravanan, Ponnusamy
Correspondence regarding the use of different diagnostic tests for gestational diabetes.
Predictors of metformin failure in gestational diabetes mellitus (GDM)
(Elsevier, 2018-05) Khin, May Oo.; Gates, Simon; Saravanan, Ponnusamy; Royal College of Obstetricians and Gynaecologists, London; University of Warwick; George Eliot Hospital, Nuneaton; Diabetes and Endocrinology; Medical and Dental; Saravanan, Ponnusamy
Introduction and objective: The role of metformin in gestational diabetes mellitus (GDM) is also increasing. However, almost half of metformin-treated women required additional insulin. Therefore, identifying the characteristics of these women may help define optimal therapeutic strategy. Methods: This is a retrospective cohort study done in a District General Hospital, UK. GDM was diagnosed by 75 g OGTT test between 24 and 28 weeks of gestation with fasting levels of ≥6.1 mmol/l and/or 2 h postprandial (PP) level of ≥7.8 mmol/l. Logistic regression and receiver operator curves (ROC) were performed to identify the predictors of metformin failure. Results: Out of 228 women with GDM included, 46/228 (20.2%) and 151/228 (66.2%) received insulin and metformin as first-line medication respectively. Among the metformin-treated, 13 stopped treatment and were excluded from analysis. Of the included 138 metformin-treated women, 77 (55.8%) required supplementary insulin (metformin failure). Metformin failure group had higher maternal age and fasting glucose level at OGTT, HbA1c at OGTT and earlier gestational age (GA) at medication initiation. Metformin failure was predicted if fasting OGTT level >4.8 mmol/l (69% sensitivity and 62% specificity). If the fasting levels of IADPSG (International Association of Diabetes and Pregnancy Study Groups) criteria and NICE (National Institute of Health and Care Excellence) were used, the positive predictive value was 78% and 77% respectively. Conclusion: As women with higher fasting glucose levels have higher chance of necessitating insulin in later pregnancies, appropriate addition of insulin at metformin initiation for these women could help better glycaemic control throughout pregnancy.
Association of maternal vitamin B and folate levels in early pregnancy with gestational diabetes: a prospective UK cohort study (PRiDE study).
(Springer, 2021-07-22) Saravanan, Ponnusamy; Sukumar, Nithya; Adaikalakoteswari, Antonysunil; Goljan, Ilona; Venkataraman, Hema; Gopinath, Amitha; Bagias, Christos; Yajnik, Chittaranjan S; Stallard, Nigel; Ghebremichael-Weldeselassie, Yonas; Fall, Caroline H D; Surgery; Medical and Dental; Venkataraman, Hema
Aims/hypothesis: The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide in all ethnic groups. Low vitamin B12 and low/high folate levels may contribute to GDM risk, but there is conflicting evidence. Our aim is to assess the relationships of early pregnancy vitamin B12 and folate levels with the risk of GDM status at 26-28 weeks of gestation. Methods: This was a prospective, multi-centre, multi-ethnic cohort study (n = 4746) in the UK. Participants who were eligible to be selectively screened as per the National Institute for Health and Care Excellence (NICE) criteria were included in the study. Results: GDM prevalence was 12.5% by NICE and 14.7% by International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. Folate deficiency (1.3%) was rare but B12 insufficiency (42.3% at <220 pmol/l) and folate excess (36.5%) were common in early pregnancy. Early pregnancy median B12 levels were lower, and folate levels higher, in women who were diagnosed with GDM at 26-28 weeks. B12 was negatively associated with fasting plasma glucose (1 SD: -0.06 mmol/l; 95% CI -0.04, -0.08; p < 0.0001) and 2 h plasma glucose levels (-0.07 mmol/l; 95% CI -0.02, -0.12; p = 0.004). Higher B12 was associated with 14.4% lower RR of IADPSG-GDM (0.856; 95% CI 0.786, 0.933; p = 0.0004) after adjusting for key confounders (age, parity, smoking status, ethnicity, family history, household income and folate status). Approximately half of this association was mediated through BMI. Folate was positively associated with 2 h plasma glucose levels (0.08 mmol/l; 95% CI 0.04, 0.13; p = 0.0005) but its relationship with fasting plasma glucose was U-shaped (quadratic β: 0.011; p = 0.05). Higher folate was associated with 11% higher RR of IADPSG-GDM (adjusted RR 1.11; 95% CI 1.036, 1.182; p = 0.002) (age, parity, smoking status, ethnicity, family history, household income and B12 status). Although no interactions were observed for B12 and folate (as continuous variables) with glucose levels and GDM risk, a low B12-high folate combination was associated with higher blood glucose level and risk of IADPSG-GDM (adjusted RR 1.742; 95% CI 1.226, 2.437; p = 0.003). Conclusions/interpretation: B12 insufficiency and folate excess were common in early pregnancy. Low B12 and high folate levels in early pregnancy were associated with small but statistically significant changes in maternal blood glucose level and higher RR of GDM. Our findings warrant additional studies on the role of unmetabolised folic acid in glucose metabolism and investigating the effect of optimising early pregnancy or pre-conception B12 and folate levels on subsequent hyperglycaemia. Trial registration: ClinicalTrials.gov NCT03008824.
Structured group education programme and accompanying mHealth intervention to promote physical activity in women with a history of gestational diabetes: a randomised controlled trial
(Wiley, 2023-07) Khunti, Kamlesh; Sukumar, Nithya; Waheed, Ghazala; Gillies, Clare; Dallosso, Helen; Brough, Christopher; Davies, Melanie J; Fitzpatrick, Claire; Gray, Laura J.; Highton, Patrick; Rowlands, Alex; Schreder, Sally; Yates, Tom; Saravanan, Ponnusamy; University of Leicester; NIHR Applied Research Collaboration East Midlands, Leicester; University of Warwick; George Eliot Hospital NHS Trust, Nuneaton; University Hospitals of Leicester NHS Trust; Diabetes and Endocrinology; Medical and Dental; Sukumar, Nithya; Saravanan, Ponnusamy
Aims: Assess effectiveness of a hybrid intervention targeting physical activity in women with prior gestational diabetes. Methods: Randomised controlled trial with parallel arms. 293 women (35.1 ± 5.1 years; 40% ethnic minority) recruited from two hospitals and randomised to routine care or hybrid lifestyle intervention comprising two group sessions and access to a mobile web app. Primary outcome was a change in objectively measured physical activity at 12 months. Secondary outcomes included self-efficacy for exercise, quality of life and anxiety and depression. Linear regression compared outcome measures between groups. Results: 83% of intervention participants attended at least one group session, of who 66% registered to use the app. There was a non-significant increase in physical activity at 12 months (between-group difference of 0.95 mg [95% CI: -0.46 to 2.37]), equivalent to approximately 500 steps per day. Intervention participants reported higher self-efficacy for exercise (0.54, 95% CI: 0.05 to 1.102; p = 0.029), lower anxiety (-0.91, 95% CI: -1.74 to -0.09; p = 0.031), and higher quality of life (0.05, 95% CI: 0.004 to 0.09; p = 0.032), compared to controls. Conclusions: The intervention improved confidence in exercise and quality of life. Further research is needed to improve participant engagement with physical activity interventions in multi-ethnic populations with a history of gestational diabetes. Keywords: gestational diabetes; group education; mHealth; physical activity; prevention of type 2 diabetes.
Increased fetal adiposity prior to diagnosis of gestational diabetes in South Asians : more evidence for the 'thin-fat' baby
(Springer Verlag, 2017-03) Venkataraman, Hema; Ram, Uma; Craik, Sam; Arungunasekaran, Anuradhai; Seshadri, Suresh; Saravanan, Ponnusamy; University of Warwick; Seethapathy Clinic and Hospital, Chennai, India; Mediscan Systems, Mylapore, Chennai, India; George Eliot Hospital, Nuneaton.; Diabetes, Endocrinology & Metabolism; Medical and Dental; Saravanan, Ponnusamy
Aims/hypothesis: Gestational diabetes mellitus (GDM) is associated with an increased future risk of obesity in the offspring. Increased adiposity has been observed in the newborns of women with GDM. Our aim was to examine early fetal adiposity in women with GDM. Methods: Obstetric and sonographic data was collated for 153 women with GDM and 178 controls from a single centre in Chennai, India. Fetal head circumference (HC), abdominal circumference (AC), femur length (FL) and biparietal diameter (BPD) were recorded at 11, 20 and 32 weeks. Anterior abdominal wall thickness (AAWT) as a marker of abdominal adiposity at 20 and 32 weeks was compared between groups. Adjustments were made for maternal age, BMI, parity, gestational weight gain, fetal sex and gestational age. Results: Fetuses of women with GDM had significantly higher AAWT at 20 weeks (β 0.26 [95% CI 0.15, 0.37] mm, p < 0.0001) despite lower measures of HC, FL, BPD and AC. AAWT remained higher in the fetuses of women with GDM at 32 weeks (β 0.48 [0.30, 0.65] mm, p < 0.0001) despite similar measures for HC, FL, BPD and AC between groups. Both groups had similar birthweights at term. There was an independent relationship between fasting plasma glucose levels and AAWT after adjustment as described above. Conclusions/interpretation: A 'thin but fat' phenotype signifying a disproportionate increase in adiposity despite smaller or similar lean body mass was observed in the fetuses of mothers with GDM, even at 20 weeks, thus pre-dating the biochemical diagnosis of GDM. Increased AAWT may serve as an early marker of GDM.
Prevalence of prediabetes and type 2 diabetes mellitus in south and southeast Asian women with history of gestational diabetes mellitus: Systematic review and meta-analysis
(Public Library of Science, 2022-12-12) Shivashri, Chockalingam; Deepa, Mohan; Ghebremichael-Weldeselassie, Yonas; Mohan Anjana, Ranjit; Uma, Ram; Mohan, Viswanathan; Saravanan, Ponnusamy; Division of Populations, Evidence, and Technologies of Health Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom; Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, ICMR Center for Advanced Research on Diabetes, Chennai, Tamil Nadu, India; School of Mathematics and Statistics, The Open University, Milton Keynes, United Kingdom; Seethapathy Clinic & Hospital, Chennai, Tamil Nadu, India; Department of Diabetes, Endocrinology, and Metabolism, George Eliot Hospital, Nuneaton, United Kingdom.; Department of Diabetes, Endocrinology, and Metabolism, George Eliot Hospital, Nuneaton, United Kingdom.; Medical and Dental; Saravanan, Ponnusamy
Background: The burden of Gestational Diabetes Mellitus (GDM) is very high in south Asia (SA) and southeast Asia (SEA). Thus, there is a need to understand the prevalence and risk factors for developing prediabetes and type 2 diabetes mellitus (T2DM) postpartum, in this high-risk population. Aim: To conduct a systematic review and meta-analysis to estimate the prevalence of prediabetes and T2DM among the women with history of GDM in SA and SEA. Methods: A comprehensive literature search was performed in the following databases: Medline, EMBASE, Web of Knowledge and CINHAL till December 2021. Studies that had reported greater than six weeks of postpartum follow-up were included. The pooled prevalence of diabetes and prediabetes were estimated by random effects meta-analysis model and I2 statistic was used to assess heterogeneity. Results: Meta-analysis of 13 studies revealed that the prevalence of prediabetes and T2DM in post-GDM women were 25.9% (95%CI 18.94 to 33.51) and 29.9% (95%CI 17.02 to 44.57) respectively. Women with history of GDM from SA and SEA seem to have higher risk of developing T2DM than women without GDM (RR 13.2, 95%CI 9.52 to 18.29, p<0.001). The subgroup analysis showed a rise in the prevalence of T2DM with increasing duration of follow-up. Conclusion: The conversion to T2DM and prediabetes is very high among women with history of GDM in SA and SEA. This highlights the need for follow-up of GDM women for early identification of dysglycemia and to plan interventions to prevent/delay the progression to T2DM.
Investigating vitamin B12 deficiency
(BMJ Publishing Group, 2019-05-10) Sukumar, Nithya; Saravanan, Ponnusamy; University of Warwick; George Eliot Hospital, Nuneaton; Diabetes and Endocrinology; Medical and Dental; Saravanan, Ponnusamy
An article in the Rational Testing series on investigating vitamin B12 deficiency.
Low maternal vitamin B12 status is associated with lower cord blood HDL cholesterol in white Caucasians living in the UK
(MDPI, 2015-04-02) Adaikalakoteswari, Antonysunil; Vatish, Manu; Lawson, Alexander; Wood, Catherine; Sivakumar, Kavitha; McTernan, Philip. G; Webster, Craig; Anderson, Neil; Yajnik, Chittaranjan. S; Tripathi, Gyanendra; Saravanan, Ponnusamy; University of Warwick; University of Oxford; Heartlands Hospital, Birmingham; George Eliot Hospital NHS Trust, Nuneaton; University Hospitals Coventry and Warwickshire NHS Trust; Diabetes and Endocrinology; Medical and Dental; Wood, Catherine; Anderson, Neil; Saravanan, Ponnusamy
Background and aims: Studies in South Asian population show that low maternal vitamin B12 associates with insulin resistance and small for gestational age in the offspring. Low vitamin B12 status is attributed to vegetarianism in these populations. It is not known whether low B12 status is associated with metabolic risk of the offspring in whites, where the childhood metabolic disorders are increasing rapidly. Here, we studied whether maternal B12 levels associate with metabolic risk of the offspring at birth. Methods: This is a cross-sectional study of 91 mother-infant pairs (n = 182), of white Caucasian origin living in the UK. Blood samples were collected from white pregnant women at delivery and their newborns (cord blood). Serum vitamin B12, folate, homocysteine as well as the relevant metabolic risk factors were measured. Results: The prevalence of low serum vitamin B12 (<191 ng/L) and folate (<4.6 μg/L) were 40% and 11%, respectively. Maternal B12 was inversely associated with offspring's Homeostasis Model Assessment 2-Insulin Resistance (HOMA-IR), triglycerides, homocysteine and positively with HDL-cholesterol after adjusting for age and BMI. In regression analysis, after adjusting for likely confounders, maternal B12 is independently associated with neonatal HDL-cholesterol and homocysteine but not triglycerides or HOMA-IR. Conclusions: Our study shows that low B12 status is common in white women and is independently associated with adverse cord blood cholesterol.
Prevalence of gestational diabetes mellitus based on various screening strategies in western Kenya: a prospective comparison of point of care diagnostic methods
(BioMed Central, 2017-07-14) Pastakia, Sonak D.; Njuguna, Benson; Onyango, Beryl Ajwang'; Washington, Sierra; Christoffersen-Deb, Astrid; Kosgei, Wycliffe K.; Saravanan, Ponnusamy; Purdue Kenya Partnership, Kenya; Moi Teaching and Referral Hospital, Kenya; University of California, USA; University of Toronto, Canada; University of Warwick; George Eliot Hospital; Diabetes; Medical and Dental; Saravanan, Ponnusamy
Background: Early diagnosis of gestational diabetes mellitus (GDM) is crucial to prevent short term delivery risks and long term effects such as cardiovascular and metabolic diseases in the mother and infant. Diagnosing GDM in Sub-Saharan Africa (SSA) however, remains sub-optimal due to associated logistical and cost barriers for resource-constrained populations. A cost-effective strategy to screen for GDM in such settings are therefore urgently required. We conducted this study to determine the prevalence of gestational diabetes mellitus (GDM) and assess utility of various GDM point of care (POC) screening strategies in a resource-constrained setting. Methods: Eligible women aged ≥18 years, and between 24 and 32 weeks of a singleton pregnancy, prospectively underwent testing over two days. On day 1, a POC 1-h 50 g glucose challenge test (GCT) and a POC glycated hemoglobin (HbA1c) was assessed. On day 2, fasting blood glucose, 1-h and 2-h 75 g oral glucose tolerance test (OGTT) were determined using both venous and POC tests, along with a venous HbA1c. The International Association of Diabetes in Pregnancy Study Group (IADPSG) criteria was used to diagnose GDM. GDM prevalence was reported with 95% confidence interval (CI). Specificity, sensitivity, positive predictive value, and negative predictive value of the various POC testing strategies were determined using IADPSG testing as the standard reference. Results: Six hundred-sixteen eligible women completed testing procedures. GDM was diagnosed in 18 women, a prevalence of 2.9% (95% CI, 1.57% - 4.23%). Compared to IADPSG testing, POC IADPSG had a sensitivity and specificity of 55.6% and 90.6% respectively while that of POC 1-h 50 g GCT (using a diagnostic cut-off of ≥7.2 mmol/L [129.6 mg/dL]) was 55.6% and 63.9%. All other POC tests assessed showed poor sensitivity. Conclusions: POC screening strategies though feasible, showed poor sensitivity for GDM detection in our resource-constrained population of low GDM prevalence. Studies to identify sensitive and specific POC GDM screening strategies using adverse pregnancy outcomes as end points are required.