Decreased food intake with aging

Age-related Changes in Energy Intake and Weight in Community-dwelling Middle-aged and Elderly Japanese

OBJECTIVE

This study attempts to describe trends in energy intake and weight change over 12 years according to age at first participation in the study.

DESIGN

Prospective cohort study.

SETTING

The National Institute for Longevity Sciences - Longitudinal Study of Aging (NILS-LSA), a community-based study.

PARTICIPANTS

Participants included 922 men and 879 women who participated in the first study-wave (age 40-79 years) and also participated in at least one study-wave from the second to seventh study-wave. Each study-wave was conducted biennially. For individuals, the entire follow-up period was 12 years.

MEASUREMENTS

Energy intake was calculated from 3-day dietary records with photographs. Weight and height were measured under a fasting state. To estimate linear changes in energy intake and weight over 12 years according to age at first study-wave, we used the mixed-effects model.

RESULTS

Mean (SD) follow-up time and number of study-wave visits were 9.5 (3.7) years and 5.4 (1.8) times, respectively. The fixed effect of the interaction of age and time in energy intake and weight was statistically or marginally statistically significant both in men (p<0.01) and in women (p<0.06). In men, when energy intake was estimated according to age, the rate of decrease in energy intake increased from -6.8 to -33.8 kcal/year for ages 40-79 years. In women, the rate of decrease in energy intake slightly increased in older age groups (-9.1 to -16.7 kcal/year for ages 40-79 years). Weight increased in males in their 40s (0.07 kg/year from age 40) and started to decline by age 53. In women, weight started to decline around age 47 (-0.04 kg/year).

CONCLUSION

Twelve-year longitudinal data showed energy intake declined both in men and women in their 40s, and the rate of decrease increased in older males. Weight started to decline in men in their mid-50s and women in their late 40s. Further studies that focus on energy intake and weight reduction are needed to prevent weight loss or underweight in an increasingly aging society.

Environmental Strategies to Promote Food Intake in Older Adults: A Narrative Review

Aging is often accompanied by lower intakes of food energy and consequent negative effects on health. To some extent this is due to declines in physiological ability, including the sensory responsiveness to regulate food intake. Fortunately, environmental factors may still influence food intake in older adults. Factors such as social facilitation, modeling, and nutrition knowledge and skills have been shown to stimulate their food intake. While environmental factors such as the eating location, portion size, food presentation, and labeling are known to influence eating behavior, their effectiveness in stimulating food intake in older persons is not well delineated. It is suggested that improving the environmental stimuli that promote food intake is a viable strategy to overcome age-related declines in nutrient intakes. This strategy is so promising that further research is warranted.

Screening for Malnutrition in Community Dwelling Older Japanese: Preliminary Development and Evaluation of the Japanese Nutritional Risk Screening Tool (NRST)

BACKGROUND

Early and effective screening for age-related malnutrition is an essential part of providing optimal nutritional care to older populations.

OBJECTIVE

This study was performed to evaluate the adaptation of the original SCREEN II questionnaire (Seniors in the Community: Risk Evaluation for Eating and Nutrition, version II) for use in Japan by examining its measurement properties and ability to predict nutritional risk and sarcopenia in community-dwelling older Japanese people. The ultimate objective of this preliminary validation study is to develop a license granted full Japanese version of the SCREEN II.

PARTICIPANTS

The measurement properties and predictive validity of the NRST were examined in this cross-sectional study of 1921 community-dwelling older Japanese people.

MEASUREMENTS

Assessments included medical history, and anthropometric and serum albumin measurements. Questions on dietary habits that corresponded to the original SCREEN II were applied to Nutritional Risk Screening Tool (NRST) scoring system. Nutritional risk was assessed by the Geriatric Nutrition Risk Index (GNRI) and the short form of the Mini-Nutritional Assessment (MNA-SF). Sarcopenia was diagnosed according to the criteria of the European Working Group on Sarcopenia in Older People.

RESULTS

The nutritional risk prevalences determined by the GNRI and MNA-SF were 5.6% and 34.7%, respectively. The prevalence of sarcopenia was 13.3%. Mean NRST scores were significantly lower in the nutritionally at-risk than in the well-nourished groups. Concurrent validity analysis showed significant correlations between NRST scores and both nutritional risk parameters (GNRI or MNA-SF) and sarcopenia. The areas under the receiver operating characteristic curves (AUC) of NRST for the prediction of nutritional risk were 0.635 and 0.584 as assessed by GNRI and MNA-SF, respectively. AUCs for the prediction of sarcopenia were 0.602 (NRST), 0.655 (age-integrated NRST), and 0.676 (age and BMI-integrated NRST).

CONCLUSIONS

These results indicate that the NRST is a promising screening tool for the prediction of malnutrition and sarcopenia in community-dwelling older Japanese people. Further development of a full Japanese version of the SCREEN II is indicated.

Assessment of physical disability using Barthel index among elderly of rural areas of district Jhansi (U.P), India

INTRODUCTION

The health of the elderly will be an important issue defining the health status of a population. With the rise in aged population, there is a greater need to look into their physical disability aspects, which is otherwise neglected. The rationale behind the study is to assess the physical disability of the elderly living in rural area of Jhansi. The aims of the study were to study the prevalence of physical disability among the elderly of rural area, and to find out the factors and association affecting the physical disability.

METHODS

A community-based cross-sectional study was carried out in a Baragaon block of rural area of Jhansi, Uttar Pradesh, India, from July 2015 to October 2015. Multistage random sampling was performed. A total of 265 participants of age 60 years and above were selected. Physical disability was assessed using Barthel index. Appropriate data entry and statistical analysis were done in EpiInfo. Frequency tables were used to calculate the prevalence, and Chi-square test was used to find out the association.

RESULTS

The overall prevalence of physical disability was 23.4%. 70% belongs to the age group from 60 to 69 years. Physical disability was significantly higher among age group >80 years. Similarly, women were more affected with physical disability than men.

CONCLUSIONS

High prevalence of physical disability is the major area of concern. More extensive postdischarge health facilities to be provided to elderly.

The Relationship between Diet Quality and Falls Risk, Physical Function and Body Composition in Older Adults

OBJECTIVES

We aimed to examine associations between diet quality, falls risk, physical function, physical activity and body composition.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

Data collected from 171 men and women, aged 60-88 years old, as part of the Falls Risk and Osteoporosis Longitudinal Study.

MEASUREMENTS

Dietary Intake (Dietary Questionnaire for Epidemiological Studies Version 2 (DQES v2)), Falls Risk (FES-I, ABC, Berg Balance and Physiological Profile Assessment), Physical Function (SPPB), Physical Activity (PASE) and Body Composition (fat mass, lean mass, BMD, BMI, android/gynoid ratio) were ascertained. Diet quality was determined using two measures (Healthy Eating Index - HEI and Healthy Diet Indicator - HDI). One-way Analysis of Variance was used to compare mean scores between females and males and Pearson product-moment correlation coefficients were calculated to examine bivariate relationships.

RESULTS

Although females and males were analysed separately, the HDI-total score showed more associations that the HEI in both genders. The HDI showed, in females weak negative associations with BMI (r =-.21, p=.04), gynoid fat (r = -.20, p=.01), total fat mass (r = -.20, p=.02), with a weak positive association between HDI and percentage lean mass (r =.20, p=.03). Males showed positive associations between HDI and age (r =.30 p=.02) physical function (SPPB)(r =.26, p=.04), and subjective falls-risk (ABC) (r =.26, p=.03). In addition, in males, a negative association was found between HDI and FES-I (r = -.25, p=.04). The only measure that was significantly associated with the HEI-total score was the android/gynoid ratio in males (r = -.29, p=.04). When controlling for age, females demonstrated weak positive associations between gynoid (r = .19 p = .02), android (r = .19, p = .02) and total fat mass (r = .20 p = .02) as well as weak negative correlation with lean mass (r = 1.19, p = .03). Age also impacts on the FES-I (r = .29 p <.01) and ABC (r = -.23 p <.01).

CONCLUSIONS

The relationships between dietary quality and body composition, falls risk and physical function in older community dwelling, higher functioning adults appear to be gender specific. Better diet quality in females, is associated with lower BMI and fat mass, and higher lean mass, compared to males that are older and appear to have better physical function, are less likely to self-report falls risk, and have a better fat distribution i.e. a lower android/gynoid ratio have better diet quality. Furthermore, age is an important confounder and should be taken into consideration when assessing diet quality in older adults. In addition these gender and age differences may be clinically relevant and could aid in the delivery of targeted interventions.

Digestion and Postprandial Metabolism in the Elderly

The elderly are an increasing segment of the population. Despite the rapid gains in medical knowledge and treatments, older adults are more likely to experience chronic illnesses that decrease quality of life and accelerate mortality. Nutrition is a key modifiable lifestyle factor which greatly impacts chronic disease risk. Yet despite the importance of nutrition, relatively little is known of the impact of advancing age on the gastrointestinal function, the digestive responses, and the post-meal metabolic adaptations that occur in response to ingested food. Knowledge of the age-related differences in digestion and metabolism in the elderly is essential to the development of appropriate nutritional recommendations for the maintenance of optimal health and prevention of disease.

Peptides and aging: Their role in anorexia and memory

The rapid aging of the world's population has led to a need to increase our understanding of the pathophysiology of the factors leading to frailty and cognitive decline. Peptides have been shown to be involved in the pathophysiology of frailty and cognitive decline. Weight loss is a major component of frailty. In this review, we demonstrate a central role for both peripheral peptides (e.g., cholecystokinin and ghrelin) and neuropeptides (e.g., dynorphin and alpha-MSH) in the pathophysiology of the anorexia of aging. Similarly, peripheral peptides (e.g., ghrelin, glucagon-like peptide 1, and cholecystokinin) are modulators of memory. A number of centrally acting neuropeptides have also been shown to modulate cognitive processes. Amyloid-beta peptide in physiological levels is a memory enhancer, while in high (pathological) levels, it plays a key role in the development of Alzheimer's disease.

Relationship Between Self-Rated Masticatory Ability and Independent Life in Community-Dwelling Older Adults

Objective: The aim of the present study was to elucidate the influence of self-rated masticatory ability on independent living in community-dwelling older adults. Method: A total of 1,377 subjects aged 65 and over who lived in Kumamoto City, Japan were participated in a survey to investigate critical factors for self-reliance in older adults. In this study, we defined independent life in older adults as self-perceived adequate health without long-term care certification. Logistic regression analysis was used to assess self-perceived masticatory ability in relation to the independent life. Results: The population with adequate self-rated masticatory ability included a significantly higher proportion of subjects with good self-perceived health without long-term care (72.7%) than the remaining subjects (27.3%). A logistic regression analysis revealed that there was significant relationship between subjective adequate mastication and living a self-reliant healthy life (p < .001). Conclusion: Our results showed that satisfactory masticatory function was positively related to a self-reliant life with subjective healthy conditions in community-dwelling older adults, which was associated with an extended active life expectancy.

Adequacy of nutritional intake among older men living in Sydney, Australia: findings from the Concord Health and Ageing in Men Project (CHAMP)

Previous research shows that older men tend to have lower nutritional intakes and higher risk of under-nutrition compared with younger men. The objectives of this study were to describe energy and nutrient intakes, assess nutritional risk and investigate factors associated with poor intake of energy and key nutrients in community-dwelling men aged ≥75 years participating in the Concord Health and Ageing in Men Project - a longitudinal cohort study on older men in Sydney, Australia. A total of 794 men (mean age 81·4 years) had a detailed diet history interview, which was carried out by a dietitian. Dietary adequacy was assessed by comparing median intakes with nutrient reference values (NRV): estimated average requirement, adequate intake or upper level of intake. Attainment of NRV of total energy and key nutrients in older age (protein, Fe, Zn, riboflavin, Ca and vitamin D) was incorporated into a 'key nutrients' variable dichotomised as 'good' (≥5) or 'poor' (≤4). Using logistic regression modelling, we examined associations between key nutrients with factors known to affect food intake. Median energy intake was 8728 kJ (P5=5762 kJ, P95=12 303 kJ), and mean BMI was 27·7 (sd 4·0) kg/m2. Men met their NRV for most nutrients. However, only 1 % of men met their NRV for vitamin D, only 19 % for Ca, only 30 % for K and only 33 % for dietary fibre. Multivariate logistic regression analysis showed that only country of birth was significantly associated with poor nutritional intake. Dietary intakes were adequate for most nutrients; however, only half of the participants met the NRV of ≥5 key nutrients.

Anorexia of Aging

The anorexia of aging is common, leading to adverse health consequences. As populations age, the impacts from anorexia in the older population are set to increase. Only greater awareness will allow for prevention or early intervention. This article discusses the physiologic anorexia of aging, highlights contributing factors, and proposes management strategies, including screening, especially in primary care. Many neuroendocrine factors have been implicated in the pathophysiology; it is clear that further human research is necessary if there is to be a pharmacologic breakthrough. There are currently no approved pharmacologic treatment strategies to prevent or treat the anorexia of aging.

Chronic Oxytocin Administration as a Treatment Against Impaired Leptin Signaling or Leptin Resistance in Obesity

This review summarizes the existing literature on the effects of oxytocin administration in the treatment of obesity in different animal models and in humans, focusing on the central control of food intake, the oxytocin effects on adipose tissue, and the relationships between oxytocin and leptin. Oxytocin is a hypothalamic nonapeptide synthesized mainly in the paraventricular and supraoptic nuclei projecting to the pituitary, where it reaches the peripheral circulation, as well as to other brain regions. Moreover, leptin modulates oxytocin levels and activates oxytocin neurons in the hypothalamic paraventricular nucleus, which innervates the nucleus of the solitary tract, partly responsible for the brain-elicited oxytocin effects. Taking into account that oxytocin is located downstream leptin, it was hypothesized that oxytocin treatment would be effective in decreasing body weight in leptin-resistant DIO animals, as well as in those with leptin or with leptin receptor deficiency. Several groups have demonstrated that in such animal models (rats, mice, and rhesus monkeys), central or peripheral oxytocin administration decreases body weight, mainly due to a decrease in fat mass, demonstrating that an oxytocin treatment is able to partly overcome leptin deficiency or resistance. Moreover, a pilot clinical study demonstrated the efficiency of oxytocin in the treatment of obesity in human subjects, confirming the results obtained in the different animal models. Larger multicenter studies are now needed to determine whether the beneficial effects of oxytocin treatment can apply not only to obese but also to type 2 diabetic patients. These studies should also shed some light on the molecular mechanisms of oxytocin action in humans.

Clinical update on nursing home medicine: 2013

This is the seventh article in the series of Clinical Updates on Nursing Home Care. The topics covered are antiresorptive drugs, hip fracture, hypertension, orthostatic hypotension, depression, undernutrition, anorexia, cachexia, sarcopenia, exercise, pain, and behavioral and psychological symptoms of dementia.

Trends in dietary carbohydrate consumption from 1991 to 2008 in the Framingham Heart Study Offspring Cohort

The intake of carbohydrates has been evaluated cross-sectionally, but not longitudinally in an ageing American adult population. The aim of the present study was to examine trends in the intake of dietary carbohydrates and their major food sources among the Framingham Heart Study Offspring (FOS) cohort, which had been uniquely tracked for 17 years in the study. The FOS cohort was recruited in 1971-1975. Follow-up examinations were conducted, on average, every 4 years. Dietary data collection began in 1991 (examination 5) using a validated semi-quantitative FFQ. The study included 2894 adults aged ≥ 25 years with complete dietary data in at least three examinations from 1991 to 2008. Descriptive statistics were generated using SAS version 9.3, and a repeated-measures model was used to examine trends in the intake of carbohydrates and their food sources in the whole sample, and by sex and BMI category. Over 17 years of follow-up, the percentage of energy from total carbohydrates (51·0-46·8 %; P for trend < 0·001) and total sugars (18·2-16·6 %; P for trend < 0·001) decreased. There was a decrease in the percentage of energy from fructose (5·4-4·7 %; P for trend < 0·001) and sucrose (9·8-8·8 %; P for trend < 0·001). Dietary fibre intake increased (18·0-19·2 g/d; P for trend < 0·001). The number of weekly servings of yeast bread, soft drinks/soda, cakes/cookies/quick breads/doughnuts, potatoes, milk, pasta, rice and cooked grains, fruit juice/drinks, potato chips/maize chips/popcorn, and lunch foods (e.g. pizzas and burgers) decreased significantly (P for trend < 0·001), while the intake of ready-to-eat cereals, legumes, fruits, dairy products, candy and ice cream/sherbet/frozen yogurt increased significantly (P for trend<0·04). Similar trends were observed when the analyses were stratified by sex and BMI. The present results suggest favourable trends in dietary carbohydrate consumption, but dietary guidelines for fruits, vegetables and fibre were not met in this cohort.

Focus on Feeding! Evaluation of a framework for maximizing mealtime in aged care facilities

Unintentional weight loss is a health risk for residents of aged care facilities, a concern for families and places demands on nursing staff. An existing weight loss framework to assess and manage residents' weight developed by a multidisciplinary team was implemented and evaluated with nurses and residents in aged care facilities within an area health service of Sydney, Australia. Thematic analysis generated seven binary concepts relating to relational, procedural, behavioural, physical, psychological, environmental and temporal aspects of feeding assistance provided by nurses to residents. Theoretical sampling was applied to the literature confirming those concepts which were organized as a model of feeding assistance labelled the Focus on Feeding! Decision Model. Nurses can play a pivotal role in the assessment of feeding difficulty and implementation of innovative mealtime programs. The Model aims to promote nurses' critical thinking and decision-making to improve nutritional intake of residents and avoid preventable weight loss.

Descriptive epidemiological study of food intake among Japanese adults: analyses by age, time and birth cohort model

BACKGROUND

Although food and nutrient consumption among the Japanese population, known to have one of the longest life expectancies in the world, has changed markedly after World War II, little is known about the influences age, time and birth cohort have had. The present study examined the effects age, time and birth cohort have had on intake of 14 food groups from 1989 to 2009, using published data from the National Health and Nutrition Survey in Japan.

METHODS

The survey included 575 adults (271 men and 304 women) in 1989, 8431 (3952 men and 4479 women) in 1999 and 5632 (2629 men and 3003 women) in 2009. The effects of age on energy-adjusted food intakes defined by gender and birth cohort (birth in 1930-1939, 1940-1949, 1950-1959, 1960-1969, 1970-1979) were estimated using the mean polish process.

RESULTS

Intakes of meat and confectionary increased whereas those of milk and dairy products, sugar, and fats and oils decreased from 1989 to 2009. Both men and women in the 1940's birth cohort consumed more fruit, although differences in food intake by birth cohort were less discernible. Furthermore, meat, fats and oils, and wheat intake decreased while fruits, fish, beans and vegetables consumption increased with aging in both men and women.

CONCLUSIONS

The present analysis suggests intakes of meat and confectionary have increased in Japan over the past 20 years regardless of age and generation. Also, younger individuals are less likely to consume fruits, fish, beans and vegetables regardless of the birth cohort and time period. Differences in food group consumption by birth cohorts born between 1930 and 1979 were not obvious. The first indication of these findings would be that in order to avoid ongoing increases in meat and confectionery intake, the public health strategy should target the whole Japanese population. Secondly, intervening with the diet of younger individuals, especially today, would be reasonable as it is unknown whether today's younger individuals will adopt a healthier diet when they age as the other generations did.

Trends in dietary fat and high-fat food intakes from 1991 to 2008 in the Framingham Heart Study participants

Few longitudinal studies carried out in US adults have evaluated long-term dietary fat intakes and compared them with the national recommendations during the two-decade period when the prevalence of obesity and insulin resistance increased substantively. In the present study, we examined trends in the intakes of dietary fats and rich dietary sources of fats in the Framingham Heart Study Offspring Cohort over a 17-year period. The cohort was established in 1971-75 with follow-up examinations being conducted approximately every 4 years. Dietary data were collected using a semi-quantitative FFQ beginning in 1991 (exam 5). We included 2732 adults aged ≥ 25 years with complete dietary data in at least three examinations from 1991 to 2008. Descriptive statistics were generated using SAS version 9.3, and a repeated-measures model was used to examine trends in macronutrient and food intakes using R. Over the 17 years of follow-up, the percentage of energy derived from total fat and protein increased (27·3-29·8% of energy and 16·8-18·0% of energy, respectively) and that derived from carbohydrate decreased (51·0-46·8% of energy; P-trend < 0·001). Increases in the percentage of energy derived from all fat subtypes were observed, except for that derived from trans-fats, which decreased over time (P-trend < 0·001). Trends were similar between the sexes, although women exhibited a greater increase in the percentage of energy derived from saturated fat and less reduction in the percentage of energy derived from trans-fats (P interaction < 0·05). Trends in fat intake were similar across the BMI categories. The number of weekly servings of cheese, eggs, ice cream desserts, nuts, butter and sausages/processed meats increased, whereas the intake of milk, margarine, poultry, confectioneries, chips and breads decreased (P-trend < 0·001). In this cohort of predominantly Caucasian older adults, the percentage of energy derived from dietary fats increased over time, but it remained within the national recommendations of less than 35 % of total energy, on average.

Serum micronutrient status and nutrient intake of elderly Yoruba people in a slum of Ibadan, Nigeria

OBJECTIVE

The present study was conceived in response to a perceived lack of data about the nutritional status of free-living elderly Yoruba people living in a poor urban area in south-western Nigeria. The major focus was to assess the micronutrient status of elderly Yoruba people living in a slum of Ibadan.

DESIGN

A cross-sectional descriptive study was designed to collect data on dietary intake and micronutrient status.

SETTING

By means of a structured questionnaire and the estimated food record method, nutrient intake was assessed. Blood was taken from 120 people to determine serum micronutrient levels.

SUBJECTS

A total of 240 elderly Yoruba people were selected from Ibadan, Oyo State, Nigeria using a random sampling technique.

RESULTS

The diet of the elderly Yoruba participants was mainly plant based and inadequate in B vitamins (especially B1, B6 and folic acid) and micronutrients such as Zn. The intake of vitamin A ranged from 269 to 487 μg/d, while vitamin B1 and B2 intakes ranged from 0·20 to 0·82 mg/d in both males and females. The intake of vitamin C varied from 24·8 to 42·8 mg/d. The majority of participants had insufficient serum levels of vitamins and minerals relative to reference values. Forty per cent were deficient in serum Ca, 71% were deficient in serum Zn and 51% were deficient in serum 25-hydroxyvitamin D.

CONCLUSIONS

The majority of the elderly Yoruba people were deficient in Zn, ferritin and vitamin B6. This is the result of a diet lacking in vitamins and minerals.

Olfactory disorders and quality of life--an updated review

Olfactory disorders are common and affect about one-fifth of the general population. The main causes of olfactory loss are post viral upper respiratory infection, nasal/sinus disease, and head trauma and are therefore very frequent among patients in ear, nose, and throat clinics. We have systematically reviewed the impact of quantitative, qualitative, and congenital olfactory disorders on daily life domains as well as on general quality of life and depression. From the extensive body of literature, it can be concluded that loss of the sense of smell leads to disturbances in important areas, mainly in food enjoyment, detecting harmful food and smoke, and to some extent in social situations and working life. Most patients seem to deal well and manage those restrictions. However, a smaller proportion has considerable problems and expresses a noticeable reduction in general quality of life and enhanced depression. The impact of coping strategies is discussed.

Effects of individual dietary counseling as part of a comprehensive geriatric assessment (CGA) on nutritional status: a population-based intervention study

BACKGROUND

Nutritional risk is relatively common in community-dwelling older people.

OBJECTIVE

To objective of this study was to evaluate the effects of individual dietary counseling as part of a Comprehensive Geriatric Assessment on nutritional status among community-dwelling people aged 75 years or older.

METHODS

Data were obtained from a subpopulation of participants in the population-based Geriatric Multidisciplinary Strategy for the Good Care of the Elderly (GeMS) intervention study in 2004 to 2007. In the present study, the population consist 173 persons at risk of malnutrition in the year 2005 in an intervention (n=84) and control group (n=89). Nutritional status, body weight, body mass index, serum albumin were performed at the beginning of the study and at a two-year follow-up. The nutritional screening was performed using the Mini Nutritional Assessment (MNA) test.

RESULTS

A increase in MNA scores (1.8 95% confidence interval [CI]: 0.7 to 2.0) and in serum albumin (0.8 g/L, 95% CI: 0.2 to 0.9 g/L) were a significant difference between the groups.

CONCLUSIONS

Nutritional intervention, even dietary counseling without nutritional supplements, may improve nutritional status.

Anorexia of aging and gut hormones

We are expected to live longer than if we had been born 100 years ago however, the additional years are not necessarily spent in good health or free from disability. Body composition changes dramatically over the course of life. There is a gradual increase in body weight throughout adult life until the age of about 60-65 years. In contrast, body weight appears to decrease with age after the age of 65-75 years, even in those demonstrating a previous healthy body weight. This age related decrease in body weight, often called unintentional weight loss or involuntary weight loss can be a significant problem for the elderly. This has been shown to be related to decline in appetite and food intake is common amongst the elderly and is often referred to the anorexia of aging. Underlying mechanisms regulate energy homeostasis and appetite may change as people age. In this review, peripheral factors regulating appetite have been summarized in regards to their age-dependent changes and role in the etiology of anorexia of aging. Understanding the alterations in the mechanisms regulating appetite and food intake in conjunction with aging may help inform strategies that promote healthy aging and promote health and wellbeing in the elderly years, with the end goal to add life to the years and not just years to our lives.

Determinants of foodservice satisfaction for patients in geriatrics/rehabilitation and residents in residential aged care

BACKGROUND

Poor satisfaction with institutional food is a significant moderator of food intake in geriatrics/rehabilitation and residential aged care.

PURPOSE

To quantify the relationship between foodservice satisfaction, foodservice characteristics, demographic and contextual variables in geriatrics/rehabilitation and residential aged care.

METHODS

The Resident Foodservice Satisfaction Questionnaire was administered to 103 patients of 2 geriatrics/rehabilitation units and 210 residents of nine residential aged care facilities in Brisbane, Australia. Ordered probit regression analysis measured the association of age, gender, ethnicity and appetite, timing and amount of meal choice, menu selectivity, menu cycle, production system, meal delivery system and therapeutic diets with foodservice satisfaction.

RESULTS

Patient and resident appetite (P < 0.01), the amount and timing of meal choice (P < 0.01), self-rated health (P < 0.01), accommodation style (P < 0.05) and age (P < 0.10) significantly moderated foodservice satisfaction. High protein/high energy therapeutic diets (P < 0.01), foodservice production (P < 0.01) and delivery systems (P > 0.01) were significant moderators for those with 'fair' self-rated health.

CONCLUSIONS

Patient and resident characteristics and structural and systems-related foodservice variables were more important for influencing foodservice satisfaction than characteristics of food quality. The results suggest modifications to current menu planning and foodservice delivery methods: reducing the time-lapse between meal choice and consumption, augmenting the number of meals at which choice is offered, and revising food production and delivery systems.It is important that residents in poorer health who are a high risk of under-nutrition are provided with sufficient high protein/high energy therapeutic diets. Diets that restrict macro- and micro-nutrients should be minimized for all patients and residents.

Anorexia and eating patterns in the elderly

Objectives

To evaluate the change in eating habits occurring in community- dwelling and institutionalized elderly subjects with senile anorexia.

Design

Cross- sectional, observational.

Setting

Community, nursing homes and rehabilitation or acute care facilities in four Italian regions.

Participants

A random sample of 526 subjects, aged 65 years and older (217 free living individuals, 213 residents in nursing homes, and 93 patients in rehabilitation and acute wards).

Measurements

All subjects underwent a multidimensional geriatric evaluation of: nutritional status, anthropometric parameters, health and cognitive status, depression, taste, chewing and swallowing function, and some hormones related to appetite. Diet variety was assessed, considering the frequency of consumption of different food groups (milk and dairy products; meat, fish, and eggs; cereals and derivatives; fruit and vegetables).

Results

In anorexic elderly subjects the global food intake was reduced, and the eating pattern was characterized by the reduced consumption of certain food groups (“meat, eggs and fish” and “fruit and vegetables”) whereas the frequency of consumption of milk and cereals remained almost unchanged. Nutritional parameters were significantly better in normal eating subjects and correlated with diet variety.

Conclusion

Because of the high prevalence of senile anorexia in the geriatric population and its impact on the nutritional status, further research should be prompted to establish an intervention. protocol allowing the early diagnosis of anorexia of aging, aimed at identifying its causes and at optimizing treatment of anorexic patients.

Influence of psychosocial factors on the energy and protein intake of older people on dialysis

OBJECTIVE

To explore the relationship between nutritional parameters and psychosocial factors in older people on dialysis.

DESIGN

A cross-sectional observational study in prevalent older people on hemodialysis (HD) and peritoneal dialysis (PD).

SETTING

A secondary analysis from a quality of life study in older people (Broadening Options for Long-term Dialysis in the Elderly).

SUBJECTS

One-hundred and six patients 65 years of age or older and on dialysis for at least 90 days were purposively recruited (HD patients matched to PD patients by age, sex, dialysis vintage, ethnicity and Index of Deprivation). Half were on HD, the mean age was 72.7 years, 72% were male, 92% were from a White ethnic background, and 26% had diabetes.

INTERVENTION

The patients attended one visit at which they completed nutritional assessments (3-day food diary, subjective global assessment, handgrip strength, and body mass index) and questionnaires: Short Form-12 (SF-12), the Hospital Anxiety and Depression Scale (HADS), the Mini Mental State Exam, and social networks.

MAIN OUTCOME MEASURES

The differences in nutritional parameters between patients on PD and HD were determined by univariate analyses, and the relationships between nutritional intake and demographic, clinical, and psychosocial variables were determined by multivariate analyses.

RESULTS

There was no difference in the energy and protein intake and nutritional status between older people on HD and PD. For the whole sample, multivariate analyses found that lower energy intake was related to fewer social networks (P = .002) and lower SF-12 Physical Component Scale (PCS) scores (P = .021). A lower protein intake was related to worsening Index of Deprivation scores (P = .028) and an interaction between SF-12 PCS and presence of possible depression (P = .015).

CONCLUSION

Energy and protein intake in older people (regardless of modality) appears to be independently associated with psychosocial variables.

Gastrointestinal peptides, gastrointestinal motility, and anorexia of aging in frail elderly persons

BACKGROUND

The mechanisms involved in anorexia in frail elderly people remain unclear. The objective of this study was to establish whether fasting and postprandial levels of gastrointestinal peptides, gastrointestinal motility, and hunger are modified by age and frailty.

METHODS

Three groups of subjects were studied: (a) frail elderly (>70 years) persons, (b) non-frail elderly (>70 years) persons, and (c) healthy adults (aged 25-65 years). After an overnight fast, participants ingested a 400 Kcal liquid meal and appetite, hormonal, and gastrointestinal responses were monitored during early (0-60 min) and late (60-240 min) postprandial periods.

KEY RESULTS

Frail persons showed poor nutritional status, sarcopenia, and almost absence of hunger during fasting and postprandial periods. Older persons presented higher levels of glucose and insulin during fasting, enhanced postprandial CCK release in early postprandial period and postprandial hyperglycemia and hyperinsulinemia, but similar ghrelin levels than younger adults. Ultrasound scan showed that the fasting antral area was higher and antral compliance lower in old persons. The paracetamol absorption test showed enhanced postprandial gastric emptying in the frail. Non-gallbladder contractors showed no CCK peak in younger and non-frail groups, but the same high CCK peak as contractors in the frail.

CONCLUSIONS & INFERENCES

Frailty was associated with anorexia, risk of malnutrition, and sarcopenia. Frail persons showed impaired gastric motility (larger antral area at rest, impaired antral compliance, and enhanced postprandial emptying), impaired gallbladder motility, and fasting and/or postprandial alterations in CCK, glucose, and insulin release. Further studies are needed to determine if these factors may contribute to anorexia of aging in frail persons.

Malnutrition in elderly: social and economic determinants

Malnutrition occurs frequently in the frailest groups of the population, especially in people who are on a low income and elderly subjects, overall if they are institutionalized. The aim of this study was to assess the prevalence of malnutrition in a sample of elderly people living in different settings and to identify the determinants of malnutrition.

METHODS

A total of 718 subjects, 472 females (F) and 246 males (M), were recruited from nursing homes or were free living in three different regions in Italy. Nutritional status, depression, social, functional and cognitive status, were evaluated.

RESULTS

According to the Mini Nutritional Assessment (MNA), a high prevalence of malnutrition was found out in both genders: 26% of F and 16.3% of M were classified as being malnourished (MNA<17); 40.9% of F and 35% of M were at risk of malnutrition (MNA 17-23,5). The prevalence of malnutrition was significantly higher in NH subjects in both sexes. Moreover, a relationship was shown between malnutrition and inability to shop, prepare and cook meals because of a low income, distance from markets or supermarkets as well as impossibility to drive the car or to use public transportation. This study confirms the necessity to routinely perform nutritional status evaluation in elderly subjects, to carry out training courses for health workers (doctors, nurses, psychologists, dietitians), to implement nutritional education of the geriatric population, to develop tools and guidelines for health workers and caregivers, to identify and reduce clinical, functional, social or economic risk factors for malnutrition.

Simple kcal/kg formula is comparable to prediction equations for estimating resting energy expenditure in older cognitively impaired long term care residents

OBJECTIVE

Assessment of energy needs is a critical step in developing the nutrition care plan, especially for individuals unable to modulate their own energy intakes. The purpose of this study was to assess precision and accuracy of commonly used prediction equations in comparison to measured resting energy expenditure in a sample of "oldest old" adults residing in long term care (LTC).

SUBJECTS AND DESIGN

Resting energy expenditure (mREE) was measured by indirect calorimetry in 45 residents aged 86.1 ± 7.3 years, and compared to frequently used prediction equations (pREE): Mifflin St.Jeor, Harris Benedict, World Health Organization and Owen. Precision and accuracy were determined by concordance correlation coefficients and number of individuals within ± 10% of mREE. Bland Altman plots with linear dependence trends were constructed to visualize agreement. To complete analyses, the common 25 kcal/kg formula was assessed and alternative formulas were determined for best fit by regressing adjusted mREE on body weight.

RESULTS

mREE averaged 976.2 ± 190.3 kcal/day for females and 1260.0 ± 275.9 kcal/d for males. The strength of the relationships between pREE and mREE were only moderate (r = 0.41 - 0.72). In examining linear trends in the Bland Altman plots, significant systematic deviation from mREE was detected for all pREE. Two kcal/kg formulas were generated: 20.6 kcal/kg for females and 22.7 kcal/kg for males, which were not significantly different.

CONCLUSION

None of the prediction equations adequately estimated energy needs in this sample of the "oldest old." A simple formula using 21-23 kcal/kg may be a more practical and reliable method to determine energy needs in the LTC setting.

Evaluation of chewing ability and its relationship with activities of daily living, depression, cognitive status and food intake in the community-dwelling elderly

AIM

The aim of this study was to assess chewing ability using color-changeable chewing gum and to show the association between chewing ability and geriatric functions, as well as dietary status in the community-dwelling elderly.

METHODS

The study population consisted of 269 community-dwelling elderly aged ≥ 75 living in Tosa, Japan. Assessment of chewing ability was carried out by a dentist using color-changeable chewing gum. Activities of daily living (ADL), depression and subjective quality of life (QOL) were assessed by questionnaire. Cognitive status was assessed by; Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale-Revised (HDS-R) and Frontal Assessment Battery (FAB) during the check-up. Food diversity was assessed using the 11-item Food Diversity Score Kyoto (FDSK-11).

RESULTS

Number of teeth was significantly related to chewing ability (P<0.001). The participants with low chewing ability had significantly lower ADL scores in the items of self-maintenance (P=0.029) and intellectual activity (P=0.021). There was a significant association between low chewing ability and depression (P<0.001). Lower cognitive functions were significantly related to low chewing ability; MMSE (P=0.022), HDSR (P=0.017) and FAB (P=0.002). The participants with low chewing ability had lower food variety (P<0.001), and less frequent intake of beans, vegetables, seaweed and nuts, than the participants with high chewing ability.

CONCLUSION

Low chewing ability evaluated by color-changeable gum was associated with lower ADL, lower cognitive functioning, depression and food insufficiency in the community-dwelling elderly. More attention should be paid to assessing chewing ability of elderly persons in community settings.

Eating disorder symptoms and weight and shape concerns in a large web-based convenience sample of women ages 50 and above: results of the Gender and Body Image (GABI) study

OBJECTIVE

Limited research exists on eating disorder symptoms and attitudes and weight and shape concerns in women in midlife to older adulthood. We conducted an online survey to characterize these behaviors and concerns in women ages 50 and above.

METHOD

Participants (n = 1,849) were recruited via the Internet and convenience sampling.

RESULTS

Eating disorder symptoms, dieting and body checking behaviors, and weight and shape concerns were widely endorsed. Younger age and higher body mass index (BMI) were associated with greater endorsement of eating disorder symptoms, behaviors, and concerns.

DISCUSSION

Weight and shape concerns and disordered eating behaviors occur in women over 50 and vary by age and BMI. Focused research on disordered eating patterns in this age group is necessary to develop age-appropriate interventions and to meet the developmental needs of an important, growing, and underserved population.

Weight loss and Alzheimer's disease: temporal and aetiologic connections

The intermediate and advanced stages of Alzheimer's disease (AD) are frequently associated with weight loss (WL), but WL may even precede the onset of cognitive symptoms. This review focuses on the possible aetiologic and temporal relationships between AD and WL. When WL occurs some years before any signs of cognitive impairment, it may be a risk factor for dementia due to deficiency of several micronutrients, such as vitamins and essential fatty acids, and consequent oxidative tissue damage. The leptin reduction associated with WL may also facilitate cognitive decline. The mechanisms potentially inducing WL in AD include lower energy intake, higher resting energy expenditure, exaggerated physical activity, or combinations of these factors. A hypermetabolic state has been observed in animals with AD, but has not been confirmed in human subjects. This latter mechanism could involve amyloid assemblies that apparently increase the circulating cytokine levels and proton leakage in mitochondria. WL may be caused by patients’ increased physical activity as they develop abnormal motor behaviour (restlessness and agitation) and waste energy while trying to perform daily activities. During the course of AD, patients usually find it increasingly difficult to eat, so they ingest less food. AD-related neurodegeneration also affects brain regions involved in regulating appetite. The caregiver has an important role in ensuring an adequate food intake and controlling behavioural disturbances. In conclusion, WL is closely linked to AD, making periodic nutritional assessments and appropriate dietary measures important aspects of an AD patient's treatment.

Metabolic syndrome markers in wistar rats of different ages

In recent decades, metabolic syndrome has become a public health problem throughout the world. Longitudinal studies in humans have several limitations due to the invasive nature of certain analyses and the size and randomness of the study populations. Thus, animal models that are able to mimic human physiological responses could aid in investigating metabolic disease. Thus, the present study was designed to analyze metabolic syndrome markers in albino Wistar rats (Rattus norvegicus) of different ages. The following parameters were assessed at two (young), four ( adult), six (adult), and twelve (mature) months of age: glucose tolerance (glucose tolerance test); insulin sensitivity (insulin tolerance test); fasting serum glucose, triglycerides, total cholesterol, HDL cholestero, and LDL cholesterol concentrations; glucose uptake in isolated soleus muscle; and total lipid concentration in subcutaneous, mesenteric, and retroperitoneal adipose tissue. We found that aging triggered signs of metabolic syndrome in Wistar rats. For example, mature rats showed a significant increase in body weight that was associated. In addition, mature rats showed an increase in the serum concentration of triglycerides, total cholesterol, and LDL cholesterol, which is characteristic of dyslipidemia. There was also an increase in serum glucose compared with the younger groups of animals. Therefore, aging Wistar rats appear to be an interesting model to study the changes related to metabolic syndrome.

Energy balance changes the anabolic effect of postexercise feeding in older individuals

We previously showed that consumption of protein immediately after exercise in older adults enhances nitrogen balance when energy balance (EB) is maintained. Because daily EB routinely varies, it is important to know whether benefits of postexercise protein consumption also occur with changing EB. Within an experiment, participants consumed an isonitrogenous-isocaloric diet with the timing of a protein (PRO + CHO) or carbohydrate (CHO) beverage immediately after exercise versus earlier in the day. Within hypocaloric and hypercaloric cohorts, 3-day mean nitrogen balance was not different when protein was consumed immediately after exercise, although there was a trend (p = .09) for higher nitrogen balance in the positive EB. However, when data from our three studies were combined, the anabolic effect of postexercise feeding was evident during positive EB but not negative EB. EB is therefore an important consideration in the postexercise anabolic effect of protein feeding.

Age-related increase in food spilling by laboratory mice may lead to significant overestimation of actual food consumption: implications for studies on dietary restriction, metabolism, and dose calculations

It is widely accepted that food consumption in humans declines with advanced age; however, data from mice remain controversial. Based on our previous observation that mice spill a considerable amount of food while eating, we hypothesized that increased food spillage in old mice masks actual food intake. To investigate whether mice exhibit age-associated declines in food consumption, we evaluated the actual food consumption of C57BL/6 mice at various ages by measuring both the amount of food in the food receptacle and the amount dropped to the cage bottom during feeding. We found that old mice dropped significantly more food (36% ± 8%) than young mice (18% ± 5%), which led to overestimations of food consumption, particularly in old mice. Although actual food consumption decreased in very old mice, food intake per body weight did not significantly change. These findings suggest that caution should be taken to accurately quantify food consumption by aged animals.

Senile anorexia in different geriatric settings in Italy

OBJECTIVES

Anorexia is the most frequent modification of eating habits in old age, which may lead to malnutrition and consequent morbidity and mortality in older adults. We aimed to estimate the prevalence and factors associated to anorexia in a sample of Italian older persons living in different settings. Our secondary aim was to evaluate the impact of senile anorexia on nutritional status and on eating habits, as well as on functional status.

DESIGN AND SETTING

Observational study in nursing homes, in rehabilitation and acute geriatric wards, and in the community in four Italian regions (Lazio, Sicily, Emilia-Romagna, and Veneto).

PARTICIPANTS

526 over 65 years old participants were recruited; 218 free-living subjects, 213 from nursing homes, and 96 patients from rehabilitation and acute geriatric wards in the context of a National Research Project (PRIN) from the Italian Ministry of Instruction, University and Research (2005-067913 "Cause e Prevalenza dell'Anoressia senile").

MEASUREMENTS

Anthropometric and nutritional evaluation, olfactory, chewing, and swallowing capacity, food preferences, cognitive function, functional status, depression, quality of life, social aspects, prescribed drugs, and evaluation of gastrointestinal symptoms and pain. Laboratory parameters included prealbumin, albumin, transferrin, C-reactive protein, mucoprotein, lymphocyte count, as well as neurotransmitters leptin, and ghrelin. Anorexia was considered as ≥50% reduction in food intake vs. a standard meal (using 3-day "Club Francophone de Gériatrie et Nutrition" form), in absence of oral disorders preventing mastication.

RESULTS

The overall prevalence of anorexia was 21.2% with higher values among hospitalized patients (34.1% women and 27.2% men in long-term facilities; 33.3% women and 26.7% men in rehabilitation and geriatric wards; 3.3% women and 11.3% men living in the community) and in the oldest persons. Anorexic subjects were significantly less self-sufficient and presented more often a compromised nutritional and cognitive status. Diet composition analyses of anorexic older adults revealed a lower intake of all food groups and a general tendency to a monotonous diet.

CONCLUSION

Anorexia is a frequent condition in older Italians, particularly those hospitalized, with important consequences in the nutritional and functional status. The analysis of dietary components and its quality along with the frequency of intake of single food groups may be useful to plan intervention strategies aiming to improve the nutritional and health status of older adults with anorexia. An early detection of anorexia followed by an adequate intervention in older hospitalized patients to avoid further worsening of clinical and functional status is warranted.

Age-associated reduction of stimulatory effect of ghrelin on food intake in mice

Aging is associated with a progressive decrease in appetite and food intake. We focused on the age-associated changes of the stimulatory effect of the appetite-regulating peptide, ghrelin. Food intake and the concentrations of acyl ghrelin and desacyl ghrelin in the plasma and in the stomach were measured with and without overnight fasting in young and old mice. Moreover, the food intake in response to the intraperitoneal administration of graded doses of acyl ghrelin was compared between young and old mice. Fasting drives food intake in young mice, but not in old mice. The concentrations of acyl ghrelin and desacyl ghrelin in the plasma and in the stomach were higher in the old mice than in the young mice. Food intake did not increase in old mice when stimulated by the administration of 1-3 nmol of acyl ghrelin, which could produce a significant increase in food intake in young mice. In conclusion, food intake did not increase in old mice after either overnight fasting or the administration of acyl ghrelin. The release and synthesis of ghrelin seem to be rather higher in old mice compared to young mice. These increases might be the results of compensation for the decline of receptor (and/or post-receptor) functions.

Is there a reversal in the effect of obesity on mortality in old age?

Studies of obesity and its relationship with mortality risk in older persons have yielded conflicting results. We aimed to examine the age-related associations between obesity and mortality in older persons. Data were drawn from the Cross-Sectional and Longitudinal Aging Study (CALAS), a national survey of a random sample of older Jewish persons in Israel conducted during 1989-1992. Analyses included 1369 self-respondent participants aged 75-94 from the Cross-Sectional and Longitudinal Aging Study (CALAS). Mortality data at 20-year followup were recorded from the Israeli National Population Registry. Obesity was significantly predictive of higher mortality for persons aged 75-84, but from age 85 onwards, obesity had a protective effect on mortality albeit at a nonsignificant level. Being underweight was consistently predictive of mortality. Findings suggest that the common emphasis on avoiding obesity may not apply to those advancing towards old-old age, at least as far as mortality is concerned.

Signaling proteins that influence energy intake may affect unintentional weight loss in elderly persons

After age 70 to 75 years, average body weight decreases both in ailing and healthy people because of a loss of appetite that results in reduced energy intake and the loss of body fat and lean muscle tissue. This so-called anorexia of aging predisposes elderly people to continued pathologic weight loss and malnutrition-major causes of morbidity and mortality. Health care professionals must understand the many factors involved in the anorexia of aging to help older adults prevent unintentional weight loss. Psychological, social, and cultural factors are important effectors; however, physiological factors are emphasized here because they are not thoroughly understood and they make it inherently difficult for most people to alter their body weight. Monoamines, steroid hormones (glucocorticoids and mineralocorticoids), endocannabinoids, and proteins all influence body weight. This review is an analysis of proteins from the brain, pancreas, adipose tissue, and gastrointestinal tract that are known to affect energy intake and energy balance, with an attempt to identify those factors that may change with aging. The articles included in this review were obtained by a PubMed database search using the keywords mouse OR rat OR human AND aged OR aging OR older OR elderly AND adult AND anorexia OR "unintentional weight loss," and each of the individual proteins discussed, as well as from the reference lists of those articles. The results reveal that some proteins may be important in the development of unintentional weight loss in elderly persons, whereas others may not have a significant role. However, many of the proteins that could conceivably have a role in unintentional weight loss have not yet been studied with that question in mind. Preventing unintentional weight loss in older adults is an important goal and further research on the role of proteins important for the maintenance of energy balance and the development of unintentional weight loss in elderly persons is warranted.

Calcium intake in the United States from dietary and supplemental sources across adult age groups: new estimates from the National Health and Nutrition Examination Survey 2003-2006

BACKGROUND

Adequate lifelong calcium intake is essential in optimizing bone health. Recent National Health and Nutrition Examination Survey data were used to quantify variation in calcium intake across adult age groups and to relate age-associated changes in calcium intake with energy intake. Additional goals were to assess differences in dietary calcium intake between supplemental calcium users and nonusers and to evaluate associations between age and calcium density in the diet.

DESIGN

This cross-sectional analysis determined calcium and energy intake for National Health and Nutrition Examination Survey respondents during 2003-2006. Diet was assessed with 24-hour recall and supplement use via questionnaire. Trends in median intakes for dietary calcium, total calcium, and energy across age categories were assessed using survey analysis methods. Nutrient density was represented using calcium to energy intake ratios.

RESULTS

The analyses included data from 9,475 adults. When compared to the 19- to 30-year age group, median dietary calcium intake was lower in the ≥81-year age group by 23% in men (P<0.001) and by 14% in women (P=0.003). These reductions coincided with 35% and 28% decreases, respectively, in median energy intake (P<0.001 for each sex). In contrast, the frequency of calcium supplement use increased (P<0.001) with age in both men and women. Yet, among female supplement users, the decline in median dietary calcium intake was greater than in nonusers (P=0.02). Calcium density in the diet significantly increased relative to age in men and women (P<0.001 for each sex); however, dietary and total calcium to energy ratios were insufficient to meet target ratios inferred by adequate intake standards after age 50 years.

CONCLUSIONS

Although supplemental calcium use and calcium density were highest in older age groups, they were not sufficient in meeting recommended levels. New approaches to increasing the frequency and level of calcium supplement use to enhance calcium density in diets may be necessary to reduce osteoporosis risk among older Americans.

Principles of strategic drug delivery to the brain (SDDB): development of anorectic and orexigenic analogs of leptin

The blood-brain barrier (BBB) presents a tremendous challenge for the delivery of drugs to the central nervous system (CNS). This includes drugs that target brain receptors for the treatment of obesity and anorexia. Strategic drug delivery to brain (SDDB) is an approach that considers in depth the relations among the BBB, the candidate therapeutic, the CNS target, and the disease state to be treated. Here, we illustrate principles of SDDB with two different approaches to developing drugs based on leptin. In normal body weight humans and in non-obese rodents, leptin is readily transported across the BBB and into the CNS where it inhibits feeding and enhances thermogenesis. However, in obesity, the transport of leptin across the BBB is impaired, resulting in a resistance to leptin. As a result, it is difficult to treat obesity with leptin or its analogs that depend on the leptin transporter for access to the CNS. To treat obesity, we developed a leptin agonist modified by the addition of pluronic block copolymers (P85-leptin). P85-leptin retains biological activity and is capable of crossing the BBB by a mechanism that is not dependent on the leptin transporter. As such, P85-leptin is able to cross the BBB of obese mice at a rate similar to that of native leptin in lean mice. To treat anorexia, we developed a leptin antagonist modified by pegylation (PEG-MLA) that acts primarily by blocking the BBB transporter for endogenous, circulating leptin. This prevents blood-borne, endogenous leptin from entering the CNS, essentially mimicking the leptin resistance seen in obesity, and resulting in a significant increase in adiposity. These examples illustrate two strategies in which an understanding of the interactions among the BBB, CNS targets, and candidate therapeutics under physiologic and diseased conditions can be used to develop drugs effective for the treatment of brain disease.

Mitochondrial DNA polymerase editing mutation, PolgD257A, reduces the diabetic phenotype of Akita male mice by suppressing appetite

Diabetes and the development of its complications have been associated with mitochondrial DNA (mtDNA) dysfunction, but causal relationships remain undetermined. With the objective of testing whether increased mtDNA mutations exacerbate the diabetic phenotype, we have compared mice heterozygous for the Akita diabetogenic mutation (Akita) with mice homozygous for the D257A mutation in mitochondrial DNA polymerase gamma (Polg) or with mice having both mutations (Polg-Akita). The Polg-D257A protein is defective in proofreading and increases mtDNA mutations. At 3 mo of age, the Polg-Akita and Akita male mice were equally hyperglycemic. Unexpectedly, as the Polg-Akita males aged to 9 mo, their diabetic symptoms decreased. Thus, their hyperglycemia, hyperphagia and urine output declined significantly. The decrease in their food intake was accompanied by increased plasma leptin and decreased plasma ghrelin, while hypothalamic expression of the orexic gene, neuropeptide Y, was lower and expression of the anorexic gene, proopiomelanocortin, was higher. Testis function progressively worsened with age in the double mutants, and plasma testosterone levels in 9-mo-old Polg-Akita males were significantly reduced compared with Akita males. The hyperglycemia and hyperphagia returned in aged Polg-Akita males after testosterone administration. Hyperglycemia-associated distal tubular damage in the kidney also returned, and Polg-D257A-associated proximal tubular damage was enhanced. The mild diabetes of female Akita mice was not affected by the Polg-D257A mutation. We conclude that reduced diabetic symptoms of aging Polg-Akita males results from appetite suppression triggered by decreased testosterone associated with damage to the Leydig cells of the testis.