Pauline Anand ¹, Pratibha Dwarkanath ¹, Tinku Thomas ², Anura V. Kurpad ¹

Affiliations
1 Division of Nutrition, Department of Physiology, St. John’s Research Institute, Bangalore - 560 034, IN
2 Division of Epidemiology and Biostatistics, St. John’s Research Institute, Bangalore - 560 034, IN

Abstract

It is not known whether Indian pregnant women with low Body Mass Index (BMI) have adequate protein stores to provide sufficient amino acids for the growing fetus and how this interacts with the maternal body fat (energy) stores in early pregnancy. This study aimed to measure amino acid oxidation in pregnant women with low BMI and to evaluate the influence of maternal body fat on amino acid oxidation in early pregnancy. In two experimental studies of low BMI women, leucine oxidation rates significantly reduced from 1^st to 3^rd trimester (post absorptive state, p<0.002 and fed state, p<0.003, Wilcoxon sign rank test). In the post absorptive state in the 1st trimester, leucine oxidation negatively correlated with maternal fat percentage (r=-0.32, p=0.04). Hence, it would appear that the availability of body fat as an energy store in early pregnancy could reduce the utilization of amino acid as a substrate for the energy demands of the growing feto-placental unit.

Keywords

Pregnancy, Low Body Mass Index, Protein Synthesis, Amino Acid Oxidation, 1^st Trimester, Maternal Fat Percentage.

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Sumithra Muthayya ¹, Anura V. Kurpad ¹

Affiliations
1 Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore - 560 034, IN

Abstract

Prevention of low birth weight (LBW; < 2500 g), which affects nearly 30 per cent of infants born in India, is a public health priority. LBW includes infants born prematurely (<37 weeks of gestation) or with intrauterine growth retardation (IUGR; <10^th for gestational age). Since the majority of LBW infants in India and most developing countries are a result of IUG R, studies that explore the etiology of IUGR and interventions aimed at preventing foetal growth retardation are urgently needed.

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Rebecca Kuriyan ¹, P. Parvathi Easwaran ², Anura V. Kurpad ¹

Affiliations
1 Division of Nutrition, Institute of Population Health and Clinical Research, St. John's National Academy of Health Sciences, Sarjapur Road, Bangalore - 560034, IN
2 Department of Food Service Management and Dietetics, Avinashilingam University, Coimbatore - 641 043, IN

Abstract

The FAO/WHO/UNU Expert Consultation on Energy and Protein Requirements adopted the Basal Metabolic Rate (BMR) as the basis of expressing energy requirements. The BMR is the amount of energy used for a series of functions that are essential for life. It is measured under standard conditions that include being awake in the supine position after 10 to 12 hours of fasting and eight hours of physical rest, and being in a state of mental relaxation in an ambient environmental temperature that does not elicit heat-generating or heat-dissipating processes.

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Sarita Devi ¹, Tinku Thomas ², Pratibha Dwarkanath ¹, Annamma Thomas ³, C. N. Sheela ³, Arpita Mukhopadhyay ¹, Anura V. Kurpad ¹

Affiliations
1 Division of Nutrition, St. John’s Medical College, St. John’s National Academy of Health Sciences, Bangalore-560 034, IN
2 Division of Epidemiology and Biostatistics Unit, St. John’s Medical College, St. John’s National Academy of Health Sciences, Bangalore-560 034, IN
3 Department of Obstetrics and Gynaecology, St. John’s Medical College, St. John’s National Academy of Health Sciences, Bangalore-560 034, IN

Abstract

Low intakes of quality dietary protein could affect the methionine cycle during pregnancy, which is important for fetal growth and epigenetic regulations. Since low quality protein intake is prevalent in India, it is important to define biomarkers of the low protein intake, specifically of methyl cycle homeostasis. A secondary analysis of data was performed, from a randomized intervention trial with 500 ml milk/d on south Indian pregnant women, to examine the association of dietary protein intake with concentrations of specific amino acids (methionine, glycine and serine). The subjects also underwent isotopic infusions (n = 52) for the measurement of amino acid kinetics. Dietary intakes were measured each week by multiple 24 h recall until delivery. The plasma concentrations of amino acids (methionine, serine and glycine) were compared with kinetics of methionine i.e. transmethylation, remethylation and transulfuration (TM, RM, TS) and serine to glycine conversion rates, as measured by stable isotope labeled amino acid infusion. Dietary protein intake in the 3^rd trimester correlated positively with intakes of milk and milk based food products (ρ=0.52, p<0.001) and methionine (ρ=0.97, p<0.001) and with gestational weight gain (GWG, ρ=0.32, p=0.044). While the methionine concentration did not correlate with methyl cycle flux parameters (TM, RM and TS), the plasma concentrations of conditionally essential serine and glycine were positively correlated with their respective flux rate and with RM, TM and TS rates. Further, glycine concentrations specifically correlated positively with serine to glycine conversion rates (ρ=0.32, p=0.027). Dietary protein and methionine supply are important for the conservation of methionine during pregnancy. This had an effect on GWG, but not on birth weight, though this may have been due to the relatively small sample size. The plasma concentration of glycine was correlated with the serine-glycine conversion, which affords methyl groups for the body and supplies these when dietary protein/methionine is in poor supply. This indicates that itcan act as a biomarker of the serine-glycine conversion flux rate, which increases in the presence of a poor protein supply. In general, the plasma concentrations of these conditionally essential amino acids may be biomarkers of the methyl cycle during pregnancy, but this needs to be tested in a larger sample.

Keywords

Amino Acid Kinetics, Maternal Protein Intake, Glycine, Serine, Methionine Cycle, Pregnancy.

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Sarita Devi ¹, Julian Crasta ², Tinku Thomas ³, Pratibha Dwarkanath ¹, Annamma Thomas ⁴, C. N. Sheela ⁴, Anura V. Kurpad ¹, Arpita Mukhopadhyay ¹

Affiliations
1 Division of Nutrition, St. John’s Medical College, St. John’s National Academy of Health Sciences, Bangalore-560 034, IN
2 Department of Pathology, St. John’s Medical College, St. John’s National Academy of Health Sciences, Bangalore-560 034, IN
3 Division of Epidemiology and Biostatistics Unit, St. John’s Medical College, St. John’s National Academy of Health Sciences, Bangalore-560 034, IN
4 Department of Obstetrics and Gynecology, St. John’s Medical College, St. John’s National Academy of Health Sciences, Bangalore-560 034, IN

Abstract

Maternal intake of quality protein regulates placental development and function thereby affecting fetal growth. Considering the prevalence of inadequate intakes of quality protein in Indian pregnant women, understanding the interplay between maternal supply of protein, its metabolism and fetoplacental growth becomes important. A secondary analysis of data from an open labelled-randomized intervention trial with 500 ml milk/day on south Indian pregnant women with marginally low vitamin B₁₂ status, was performed to assess the relations between placental parameters and maternal trimester 3 methyl-cycle amino acid status as well as kinetics. This analysis was performed for 42 pregnancies from the trial where placentae had been collected and placental parameters had been measured. For these pregnancies, data on trimester 3 methionine, serine and glycine kinetics as well as plasma free amino acid concentrations were available. Protein intake and plasma citrulline concentrations were positively correlated at trimester 3 (ρ = 0.34, P = 0.027). Placental weight correlated positively with methyl-cycle specific amino acid concentrations [methionine (ρ = 0.32, P = 0.0388), serine (ρ = 0.49, P = 0.0009)], methionine kinetics [total methionine flux rates (ρ = 0.42, P = 0.006), RM (ρ = 0.45, P = 0.003), TS (ρ = 0.32, P = 0.046), TM (ρ = 0.45, P = 0.004)] and with birth weight (ρ = 0.57, P < 0.001). Findings from the current study indicate that maternal amino acid availability and more importantly, maternal methionine kinetics, positively influenced placental growth, likely mediated by key amino acids such as citrulline, which is known to regulate placental blood flow and function. As an appropriately functioning placenta is indispensable for fetal growth, these findings will form the basis for detailed mechanistic explorations into the placental regulation of maternal supply of amino acid to the fetus for designing effective intervention strategies towards optimizing fetomaternal health during and after pregnancy.

Keywords

Vitamin B₁₂, Pregnancy, Glycine, Methionine, Serine, Methionine Kinetic, Amino Acids.

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Priyanka S. Bannikoppa ¹, Sheila Uthappa ², Anura V. Kurpad ¹, Indu Mani ¹

Affiliations
1 Division of Nutrition, St. John’s Research Institute, St. John’s Medical College, Bangalore, IN
2 Department of Biochemistry, St. John’s Medical College, Bangalore, IN

Abstract

Metabolic Syndrome (MS) is a combination of physiological factors that result in increased risk for developing Cardio Vascular Diseases (CVD). One factor that has traditionally been accepted as being athero-protective is High Density Lipoprotein (HDL). However increasing reports suggest that plasma levels of HDL-C do not reflect its functionality, which is mainly attributed to its cargo of antioxidant enzymes. The study was aimed at assessing key HDL-associated enzymes as potentially better biomarkers in evaluating risk of MS and thus CVD than merely HDL-C levels in an urban South Indian population. The study consisted of patients with MS (n=41) and age matched controls (n=65). Anthropometry, routine blood biochemistry and HDL associated enzyme activities were measured. Of the HDL enzymes, paraoxonase-1 (PON-1) activity was seen to be lower whereas Lecithin Cholesterol Acyl Transferase (LCAT) was higher in subjects with MS (p<0.01). Multiple logistic regression showed that low PON-1 activity and high LCAT activity had an increased AOR for MS (RR=3.8, 95% CI-1.1, 13.3, p=0.035, and RR=17.5, 95% CI-3.9, 77.5, p<0.001 respectively), independent of HDL-C levels. This study demonstrates the prevalence of impaired function of HDL enzymes in patients with MS, which might promote inflammation, oxidative stress and atherogenesis. It also suggests that estimating the activities of key HDL enzymes such as PON-1 and LCAT could improve the accuracy of MS and CVD risk prediction than mere measurement of HDL-C levels.

Keywords

CVD, HDL-C, Inflammation, LCAT, Metabolic Syndrome, PON-1.

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Priyanka S. Bannikoppa ¹, Sheila Uthappa ², Tinku Thomas ¹, Anura V. Kurpad ¹, Indu Mani ¹

Affiliations
1 Division of Nutrition, St John’s Research Institute, Bangalore, IN
2 Department of Biochemistry, St. John’s Medical College and Hospital, Bangalore, IN

Abstract

High Density Lipoprotein (HDL) is considered to be an anti-atherogenic molecule and its beneficial function is driven by a number of enzymes such as LCAT (Lecithin Cholesterol Acyl Transferase), PON1 (Paraoxonase 1), PAF-AH (Platelet-Activating Factor Acetyl Hydrolase) and CETP (Cholesteryl Ester Transfer Protein). Low HDL-C level is the most prevalent dyslipidemia seen in India and exercise is one reliable way to improve its levels. While acute exercise is known to increase HDL-C levels, not much is known about its effects on HDL functions. This study was aimed at assessing the effect of a single bout of acute aerobic exercise on key HDL functions. Ten healthy adult male volunteers (20-35 years) were made to exercise at 65-80% VO₂ max to expend 200 Kcal using a modified Bruce protocol. Plasma samples were collected at different time points (before exercise, 15 min, 1 hour, 2 hours, 4 hours, 24 hours, 48 hours post-exercise) for analysis of HDL anti-inflammatory function and its related enzyme activities. Friedman ANOVA followed by post-hoc Wilcoxon matched pair test, showed that PON1 activity increased immediately but reached significance 48 hours post-exercise (Z=-2.666, p=0.008). CETP and LCAT activities were decreased significantly at the 4^th hour post-exercise and continued to be low even up to 48 hours (Z=-2.666, p=0.008), whereas HDL-C levels, MPO activity and HDL-II did not vary significantly at different time points. Enhanced activity of the antioxidant enzyme PON1, in combination with decreased activities of pro-atherogenic enzymes CETP and LCAT suggest that even a single bout of acute exercise could be effective in eliciting athero-protective changes in HDL function independent of HDL-C levels.

Keywords

Acute Exercise, Antioxidant Enzymes, CETP, HDL-C, PON1.

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Sejil T. Verghese ¹, Maria Pauline ¹, Arun Das ², Anura V. Kurpad ¹

Affiliations
1 Department of Physiology, St. John’s Medical College, Bangalore, IN
2 Division of Nutrition, St. John’s Research Institute, Bangalore, IN

Abstract

Lysine is the limiting amino acid in the predominantly cereal and legume based typical Indian diet and its supplementation has been shown to positively affect muscle strength in short term adult and animal models; but similar studies are lacking in children. This study looked at the effect of a 3-month lysine and iron intervention on muscle strength and growth parameters in prepubertal Indian girls. The study was a randomized controlled trial conducted in 40 normal Indian girls in the 9-10 yrs age group. The control group received only iron (6.25mg) supplementation, while the intervention group received both iron and lysine supplementation that increased the lysine intake to 50mg/kg/day. Muscle strength was estimated in both upper limbs with a hand dynamometer and muscle endurance was estimated in the non-dominant hand. Height and weight were recorded to assess growth. A significant difference was seen in the increase in the non-dominant hand grip strength between the groups (intervention: 1.4 vs control: 0.2 kg, p=0.042) at the end of the study. There was a trend of increased height gain (about 25%) and weight gain (about 50%) in the intervention group compared to control group. Lysine supplementation for 3 months increased non-dominant forearm muscle strength in Indian children.

Keywords

Lysine Supplementation, Handgrip, Muscle Strength, Growth.

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Sulagna Bandyopadhyay ¹, Anura V. Kurpad ¹

Affiliations
1 St. John's Acadamy of Health Sciences, A recongnized Research Centre of University of Mysore, Division of Nutrition, St. John's Research Institute, Bengaluru, IN

Abstract

A prevalence of 18% Low Birth Weight (LBW), 38% stunting in <5y children, and 18% sarcopenia in adults have been recently reported in India. These could partly be due to a poor-quality protein intake, which could support positive birth outcomes, linear growth in children and maintenance of the adult skeletal muscle mass with appropriate exercise. Quality protein is a highly digestible protein with adequate quantity of Indispensable Amino Acids (IAA). The measurement of risk of deficient quality protein intake requires knowledge of IAA requirements and their digestibility from different food proteins. The present analyses, using dietary intake data of different age groups from the latest National Nutrition Monitoring Bureau rural survey, showed that the protein quality of rural Indian diets was suboptimal and had considerable impact on the risk of quality protein deficiency, which varied from 14 to 80% among different age groups. Modest additions of animal source foods (such as milk and egg) could alleviate the risk of quality protein deficiency in the population. Dietary protein quality should be considered while evaluating dietary interventions and framing the policy of supplementary nutrition programs for vulnerable populations.

Keywords

Dietary Protein, Amino Acids, Protein Quality, Stunting, Under Nutrition, Low Birth Weight, Animal Source Foods.

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Sulagna Bandyopadhyay ¹, Rebecca Kuriyan ¹, Anura V. Kurpad ¹

Affiliations
1 Division of Nutrition, St. John’s Research Institute, St. John’s Academy of Health Sciences, A Recognized Research Centre of University of Mysore, Bengaluru, IN

Abstract

The recent Food and Agricultural Organization / World Health Organization United Nations University expert consultations on protein quality have emphasized the need for protein digestibility measurements in humans. The standard in vivo oro-ileal protein digestibility measurements are invasive, expensive, time-consuming and burdensome on participants. The in vitro multi-enzyme based assays have been a promising tool for rapid, non-invasive and cost-effective protein digestibility measurements in foods. The digestibility estimates obtained from these methods have not been compared with true ileal digestibility measurements in humans. This study measured in vitro protein digestibility in selected commonly consumed plant and animal proteins, assessed the effect of heat-treatment on protein digestibility and compared the digestibility estimates with previously published human true ileal protein digestibility values. The in vitro protein digestibility in the raw plant proteins ranged from 35% in pigeon pea to 72% in rice. Cooking improved digestibility by 8% in potato to 26% in pigeon pea. The in vitro protein digestibility in freeze dried and spray dried milk powder were €85% which reduced to 73% after heat-treatment at 120°C for 40 minutes. The mean difference between the in vitro protein digestibility coefficients and the true ileal protein digestibility estimates was 4.3% (95% CI:-1.05, 9.74%). Although, the in vitro assays can be used as useful tools to predict ileal digestibility in humans, and to rank food proteins according to their digestibility, further studies are warranted for inter-laboratory validation of assays with appropriate evaluation on same protein sources against true ileal digestibility measured in humans.

Keywords

In vitro Protein Digestibility, Protein Quality, Plant Protein, Legume, Rice, Milk, Heat-Treatment, True Ileal Protein Digestibility.

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