Physiological studies of whey protein in older people, with a focus on feeding behaviour, nutrition, obesity, type 2 diabetes mellitus and post-prandial blood pressure

Australia’s population is ageing. Health problems are more prevalent in elderly than younger people, and lead to much of the health expenditure and health resource allocation in this and other countries. Nutritional problems are common in the elderly and often contribute to the development and worsening of health problems in older people. A particular problem is the interacting effects of under-nutrition, reduced dietary protein intake, anabolic resistance to dietary protein (the need for greater intakes to produce the same benefits, particular on muscle mass and function) and consequent muscle loss, reduced function, and in some cases the development of sarcopaenia. Both type 2 diabetes (T2D) and obesity are prevalent in older people – and often coexist. Dietary measures are key to the management of both conditions, in older as in younger adults. Protein supplements either alone or in combination with other macronutrients are increasingly recommended to, and used by, older people, to prevent and/or manage these problems. Whey protein is often used alone or as part of these supplements, as it is has particularly beneficial effects on muscle anabolism. There remain gaps in our knowledge of the effects of whey protein ingestion in older people. This thesis comprises clinical studies designed to fill some of those gaps. The studies in this thesis from five clinical trials involved assessing responses to oral whey protein ingestion particularly whey protein concentrate on feeding behaviour, nutrition, obesity, T2D and blood pressure (BP) in older and younger people with a focus on older people. Dietary protein supplementation may play a role in the management of these conditions. The principal outcomes assessed were appetite; food intake; gut hormone release; gastric emptying rate; circulating glucose, glucagon and insulin concentrations; BP and heart rate (HR). Chapter 1: Introduction focusses on rising burden of ageing in Australia and other developed countries; nutritional problems and adverse body composition changes associated with ageing i.e. undernutrition and sarcopaenia; nutritional management of under-nutrition and sarcopaenia with a focus on the effects of whey protein; rising rates of obesity, T2D and BP effects in older people and whey protein as a management strategy; gastric emptying and its effects in older people. Chapter 2 is a review of the current literature relating to the use of protein supplements in the elderly, dietary protein requirements in older people, and the effects of ageing on the gastrointestinal responses to protein ingestion. Chapter 3 describes the effect of differing whey protein loads (control, 30 g whey protein and 70 g whey protein) before breakfast on appetite and food intake at subsequent breakfast, lunch and dinner in healthy younger and older men. Energy intake was suppressed by whey protein drinks in a protein load-responsive fashion at breakfast and particularly, at lunch, but not at dinner, and suppression of energy intake by protein was less in healthy older than younger men. Cumulative protein intake was increased in a protein load responsive fashion. These findings support the use of whey-protein drink supplements in healthy older patients who aim to increase their protein intake without decreasing their overall energy intake (ACTRN12618000881235). Chapter 4 describes the effect of whey protein load on energy intake, appetite and gastric emptying in young and older, obese men. The 30 g whey protein drink did not suppress appetite or energy intake in obese younger or older men suggesting that obesity may blunt/abolish the age-related effect of whey protein on suppression of energy intake (ANZCTR12616001216404). Chapter 5 describes the effects of co-ingesting whey protein and glucose alone and combined (a drink containing either 30 g glucose, 30 g whey protein, 30 g whey-protein plus 30 g glucose or control) on blood glucose, plasma insulin and glucagon concentrations in healthy younger and older men. The addition of 30 g of whey protein to 30 g of glucose in drink form substantially attenuated the increase in blood glucose concentrations induced by glucose alone; the magnitude of the whey-induced reduction in blood glucose was not affected by age, with comparable reductions in older to those in younger adult men; the stimulation of plasma insulin concentrations by whey protein was not reduced by ageing, unlike the insulin response to glucose; whey protein suppressed hunger less in older than younger men. Glucagon concentrations were unaffected by age. These results demonstrate that the ability of whey-protein to reduce carbohydrate-induced postprandial hyperglycaemia is retained in older men and that protein supplementation may be a useful strategy in the prevention and management of T2D in older people (ACTRN12619000420145). Chapter 6 describes the effects of co-ingesting whey protein and glucose alone and combined (a drink containing either 30 g glucose, 30 g whey protein, 30 g whey-protein plus 30 g glucose or control) on blood glucose, plasma insulin and glucagon concentrations in older men with (not on injectable treatment) and without T2D. The addition of 30 g of whey protein to 30 g of glucose in drink form substantially attenuated the increase in blood glucose concentrations induced by glucose alone; the magnitude of the whey-induced reduction in blood glucose was not affected by the presence of T2D and the stimulation of plasma insulin concentrations by whey protein. The ability of whey-protein to reduce carbohydrate-induced postprandial hyperglycaemia is retained in men with T2D (ACTRN12619000420145). Chapter 7 describes the effects of age on BP and heart rate responses to whey protein in healthy younger and older men after oral ingestion of 0 g and 70 g whey protein. The older men exhibited a greater fall in SBP after whey-protein versus control than the younger men, with no BP change after the two drinks in younger men. The nadir in SBP occurred later in the older than younger men with SBP still apparently declining 180 min after whey-protein ingestion in the older men. The magnitude of the rise in HR was greater in the younger men indicating that following ingestion of 70 g whey protein, healthy older men exhibited a sustained fall in BP, despite an increase in HR, whereas in younger men there was no change in BP. BP may need to be monitored after high protein meals in older people at risk of postprandial hypotension (ACTRN12612000941864 and ACTRN12614000846628). Chapter 8 describes the BP and heart rate responses to oral protein intake in healthy older men after ingestion of 30 g and 70 g of whey protein. The older men exhibited a decrease in systolic blood pressure (SBP) after ingestion of 30 g and 70 g of whey protein to a similar degree after both the drinks and greatest between 120 and 180 mins after ingestion. HR was increased maximally after 70 g particularly in the third hour (hr) and diastolic blood pressure (DBP) decreased non significantly after protein drinks. Even modest protein loads in older men can result in postprandial hypotension (PPH) and care must be taken (ACTRN12612000941864). Chapter 9 describes the acute effects of whey protein, alone and mixed with other macronutrients in varying amounts such as 70 g whey-protein (P280); (ii) 14 g whey-protein, 28 g carbohydrate, 12.4 g fat (M280); (iii) 70 g whey-protein, 28 g carbohydrate, 12.4 g fat (M504); or (iv) a non-caloric control drink (C) on BP and heart rate in healthy older men. SBP decreased after all three nutrient drinks with the greatest reduction after the M504. Maximal decreases in SBP occurred about 2 hr after drink ingestion and were sustained thereafter. Maximum DBP decreases and HR increases occurred after M504, with no differences between the effects of the P280 and M280 drinks, thereby demonstrating that the effects of whey-protein containing drinks to lower BP and increase HR appear to be primarily dependent on their energy content rather than macronutrient composition and may persist for at least 3 hr after ingestion. Pure whey-protein drinks may represent the best approach to maximize protein intake without increasing the potential for deleterious BP falls in older people (ACTRN12614000846628).Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202

Comparative Effects of Co-Ingesting Whey Protein and Glucose Alone and Combined on Blood Glucose, Plasma Insulin and Glucagon Concentrations in Younger and Older Men

The ingestion of dietary protein with, or before, carbohydrate may be a useful strategy to reduce postprandial hyperglycemia, but its effect in older people, who have an increased predisposition for type 2 diabetes, has not been clarified. Blood glucose, plasma insulin and glucagon concentrations were measured for 180 min following a drink containing either glucose (120 kcal), whey-protein (120 kcal), whey-protein plus glucose (240 kcal) or control (~2 kcal) in healthy younger (n = 10, 29 ± 2 years; 26.1 ± 0.4 kg/m(2)) and older men (n = 10, 78 ± 2 years; 27.3 ± 1.4 kg/m(2)). Mixed model analysis was used. In both age groups the co-ingestion of protein with glucose (i) markedly reduced the increase in blood glucose concentrations following glucose ingestion alone (p < 0.001) and (ii) had a synergistic effect on the increase in insulin concentrations (p = 0.002). Peak insulin concentrations after protein were unaffected by ageing, whereas insulin levels after glucose were lower in older than younger men (p < 0.05) and peak insulin concentrations were higher after glucose than protein in younger (p < 0.001) but not older men. Glucagon concentrations were unaffected by age. We conclude that the ability of whey-protein to reduce carbohydrate-induced postprandial hyperglycemia is retained in older men and that protein supplementation may be a useful strategy in the prevention and management of type 2 diabetes in older people

Estimation of cotinine level among the tobacco users and nonusers: A cross-sectional study among the Indian population

Background: Epidemiological studies in smokers indicate a dose-response relationship between the number of cigarettes smoked per day and the risk of developing certain smoking related diseases. The alkaloid nicotine is the major pharmacologically active substance in tobacco. Objective: To estimate the cotinine level excretion in urine among smoked and smokeless tobacco users and nonsmokers among the Indian population. Materials and methods: The study sample consisted of 250 subjects who were apparently healthy, asymptomatic and not using any drug. The study sample was divided into smoked tobacco users (bidi and cigarette), smokeless tobacco users, both smoked and smokeless tobacco users and controls (non-users of tobacco in the past or present). Results: The mean Cotinine level in urine was significantly (p &ndash; value &lt; 0.05) more among smoked tobacco users in comparison to smokeless tobacco users and non-users of tobacco. Whereas, the mean Cotinine level in urine was significantly (p &ndash; value &lt; 0.05) more among smokeless tobacco users in comparison to non-users of tobacco

A cross-sectional survey to assess the effect of socioeconomic status on the oral hygiene habits

Background: It is widely accepted that there are socioeconomic inequalities in oral health. A socioeconomic gradient is found in a range of clinical and self-reported oral health outcomes. Aim: The present study was conducted to assess the differences in oral hygiene practices among patients from different socioeconomic status (SES) visiting the Outpatient Department of the Sudha Rustagi College of Dental Sciences. Materials and Methods: A cross-sectional survey was conducted from June to October 2014 to assess the effect of SES on the oral hygiene habits. The questionnaire included the questions related to the demographic profile and assessment of the oral hygiene habits of the study population. Results: Toothbrush and toothpaste were being used significantly (P < 0.05) more by lower middle class (84.4%) and upper middle class (100.0%). A significantly higher frequency of cleaning teeth (twice a day) was reported among the lower middle class (17.2%) and upper middle class (21.5%). The majority (34.3%) of the study population changed their toothbrush once in 3 months. The cleaning of tongue was reported by patients belonging to the upper middle (62.0%), lower middle (52.1%), and upper lower class (30.0%). The use of tongue cleaner was reported to be significantly (P < 0.05) more among upper middle (10.1%) class patients. A significantly higher number of patients from the lower class (81.3%) never visited a dentist. Conclusion: The oral hygiene practices of the patients from upper and lower middle class was found to be satisfactory whereas it was poor among patients belonging to lower and upper lower class

Rational use of protein supplements in the elderly—relevance of gastrointestinal mechanisms

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Positive impact of rescheduling Bacillus Calmette-Guérin vaccination on vaccinations at birth

Context: Inimitable among the trio of recommended immunizations administered to newborns at delivery centers of institutions is hepatitis B. While it is necessary for hepatitis B to be given within 24 hours of birth, the same cannot be said for Bacillus Calmette-Guérin (BCG) and zero-dose oral polio vaccine (OPV). Objective: To assess the impact of rescheduling of BCG vaccination from the current twice weekly to daily to cover newborn vaccinations at the Government Medical College, Patiala, India. Materials And Methods: Until 2015, the delivery of BCG vaccine was restricted to twice a week, but from the year 2015, the schedule was changed from twice weekly to daily. Records for the 2 years, 2014 and 2015, were obtained, i.e., before and after the change. Data on 7065 babies born from January 2014 to December 2015 were statistically analyzed for the coverage of birth dose of hepatitis B, BCG, and OPV using Microsoft Excel. Chi-square test was applied, and p < 0.05 was considered significant. Results: Rescheduling of BCG dose, from twice weekly to daily, the coverage of BCG and OPV zero dose increased from 54% (in 2014) to 78% (in 2015), and a marked increase from 8.2% to 42.9% was noted for the birth dose of hepatitis B. By rescheduling BCG (twice weekly to daily), the vaccine wastage increased from 21.5% to 26.2%, the difference found to be statistically insignificant. Conclusions: Modification in the delivery of immunization service from twice a week to daily has had a good impact on the vaccination of newborns though the goal of achieving the ideal 100% coverage is yet to be reached. Apart from the immunization of newborns, improving parental awareness, better coordination between immunization staff and maternal health staff, improved communication, and clear delineation of responsibility and answerability in the immunization service delivery will have a good impact on the vaccination of newborns

Effects of age on blood pressure and heart rate responses to whey protein in younger and older men

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Blood Pressure and Heart Rate Responses following Dietary Protein Intake in Older Men

Postprandial hypotension (PPH) occurs frequently in older people &gt;65 years old. Protein-rich supplements, particularly whey protein (WP), are increasingly used by older people for various health benefits. We have reported that 70 g WP drinks cause significant, and in some cases marked, falls in blood pressure (BP) in older men. The effects of lower, more widely used, doses (~30 g) on systolic (SBP) and diastolic (DBP) blood pressure and heart rate (HR) are not known. In a randomized order, eight older men (age: 72 ± 1 years; body mass index (BMI): 25 ± 1 kg/m2) after overnight fast ingested a drink containing (i) a non-caloric control (~2 kcal), (ii) 30 g of whey protein (120 kcal; 'WP30'), or (iii) 70 g of whey protein (280 kcal; 'WP70'). The BP and HR were measured in this pilot study with an automated device before and at 3-min intervals for 180 min following drink ingestion. Drink condition effects were determined by repeated-measures ANOVA. The SBP decreased after both WP drinks compared to the control (p = 0.016), particularly between 120 and 180 min, with no difference in the effects of WP30 and WP70. The SBP decreased by ≥20 mmHg in more than 50% of people after both WP drinks (WP30: 63%; WP70: 75%) compared to 38% after the control. The maximum fall in the SBP occurred during the third hour, with the nadir occurring latest after WP70. The DBP decreased non-significantly by several mmHg more after the WP drinks than after the control. The maximum HR increases occurred during the third hour, with the greatest increase after WP70. The SBP decreased after both WP drinks compared to the control, with the effects most evident between 120 and 180 min. Accordingly, ingestion of even relatively modest protein loads in older men has the potential to cause PPH.Published onlin

Acute effects of whey protein, alone and mixed with other macronutrients, on blood pressure and heart rate in older men

BACKGROUND: Caloric supplements are increasingly used by older people, aiming to increase their daily protein intake. These high caloric drinks, rich in glucose and whey-protein in particular, may result in potential harmful decreases in blood pressure (BP). The effect of ingesting whey-protein with glucose and fat on BP is unknown. It has also been assumed that the maximum fall in systolic blood pressure occurs within 2 h of a meal. METHODS: This study aimed to determine in older men, the effects of whey-protein, alone and mixed with other macronutrients, on systolic (SBP) and diastolic (DBP) blood pressure and heart rate (HR) in older men for 3 h. Thirteen older men (age 75 ± 2yrs; body mass index (BMI) 25.6 ± 0.6 kg/m(2)) ingested a drink on separate study days: (i) 70 g whey-protein (P(280))(;) (ii) 14 g whey-protein, 28 g carbohydrate, 12.4 g fat (M(280)); (iii) 70 g whey-protein, 28 g carbohydrate, 12.4 g fat (M(504)); or (iv) a non-caloric control drink (C). RESULTS: SBP decreased after all three nutrient drinks compared to the C, with the greatest reduction after the M(504) drink (P = 0.008). Maximal decreases in SBP (C: -14 ± 2 mmHg, P(280): -22 ± 2 mmHg, M(280): -22 ± 4 mmHg, M(504): -24 ± 3 mmHg) occurred about 2 h after drink ingestion and this fall was sustained thereafter (120-180 min: P(280) and M(504) vs. C P < 0.05). Maximum DBP decreases and HR increases occurred after M(504), with no differences between the effects of the P(280) and M(280) drinks. CONCLUSIONS: The effects of whey-protein containing drinks to lower BP and increase HR appear to be primarily dependent on their energy content rather than macronutrient composition and may persist for at least 3 h after ingestion,. Pure whey-protein drinks may represent the best approach to maximize protein intake without increasing the potential for deleterious BP falls in older people. TRIAL REGISTRATION: ACTRN12614000846628, 14/03/2019