Lifestyle factors associated with glycaemic control and body mass index in older adults with diabetes.

OBJECTIVE: To investigate the relations between lifestyle factors (diet and exercise), glycated haemoglobin (HbA(1c)) and body mass index (BMI) in older adults with diabetes. DESIGN AND SETTING: A community hospital-based cross-sectional study of 150 noninstitutionalized, ambulatory adults (>/=65 y) with diabetes, residing within New Zealand's Kapiti region. SUBJECTS: Patients were recruited from all general practices; two diabetes clinics; local diabetes society and through advertisements in community newspapers. A total of 211 eligible people were identified, but 60 refused to participate and one withdrew. In all, 150 people completed the study (71% participation rate). METHODS: Nutrient intakes were calculated by a food-frequency questionnaire. Physical activity was assessed by interview using a validated questionnaire. Medical history and demographic data were obtained by interview or self-completed questionnaires; height, weight and HbA(1c) were measured. Multivariate models using bootstrapping and stepwise linear regression were used to select factors associated with HbA(1c) and BMI. RESULTS: Each five-unit increase in energy from dietary saturated fat and five-unit increase in BMI were associated with 6% (95% confidence interval=2-10%; P=0.004) and 4% (0.3-7%; P=0.031) increases in HbA(1c), respectively. For females with moderate, compared with low overall activity, there was a 14% (7-20%; P=0.000) reduction in BMI while for males the reduction was only 5% (-1-11%; P=0.116). BMI decreased 5% (2-9%; P=0.004) with each 10-y increase in age, while a five-unit increment in energy from dietary sucrose was associated with a 6% (1-11%; P=0.025) increase in BMI. CONCLUSIONS: Reducing dietary saturated fat and excess body weight may be useful means of improving glycaemic control in older adults with diabetes. Increasing physical activity and reducing energy from dietary sucrose may assist weight control, the former particularly in women.

Selenium and zinc status are suboptimal in a sample of older New Zealand women in a community-based study.

The importance of selenium and zinc in the immune functioning of the aged is widely recognized. Seniors in New Zealand are at particularly high risk of low selenium status because of the low selenium soil environment. The zinc status of the New Zealand elderly has never been assessed. In this cross-sectional study, the biochemical selenium, zinc and lipid levels, physical functional capacity and dietary intakes of 103 randomly selected free-living New Zealand women (mean age +/- SD, 75 +/- 3 y) were assessed. Among nonusers of selenium supplements (n = 80), 80% [95% confidence interval (CI): 70; 88%] had plasma selenium levels (0.85 +/- 0.23 micromol/L) below 1.00 micromol/L [ approximately 10% below mean plasma selenium necessary for full expression of glutathione peroxidase (GPx) activity in New Zealand subjects]. Plasma selenium was strongly correlated with GPx: r = 0.56; P < 0.0001. For nonusers of zinc supplements (n = 88), serum zinc concentrations were 12.4 +/- 1.4 micromol/L, with 12% (95% CI: 6; 21%) having levels below the cut-off value (10.7 micromol/L). Estimated mean daily selenium and zinc intakes were 34 +/- 10 microg and 8.7 +/- 2.0 mg, respectively. Subjects in the highest tertile of a functional capacity index had higher biochemical zinc and selenium values than those in the lowest tertile (P < 0.05). The correlation between plasma selenium and GPx indicates that selenium intake in these women is still insufficient for full expression of GPx activity. Lower serum zinc levels also appear to be prevalent. Because a suboptimal trace element status may be more common among those with a poor physical functioning, promotion of the consumption of nutrient dense foods or supplements to improve selenium and zinc status of elderly women in New Zealand may be beneficial.

Changes in dietary intake during a 6-year follow-up of an older population.

OBJECTIVE: To examine prospective changes in food habits and nutrient intakes in a representative New Zealand sample of community dwelling adults aged 70 y and over. DESIGN: Longitudinal study with food intake data collected in 1988/89 and again in 1995/96. In an attempt to distinguish age, time and cohort effects, data were analysed longitudinally, cross-sectionally and time-sequentially. SUBJECTS: The sample for study consisted of all non-institutionalised people aged 70 years and over registered with the Mosgiel Health Centre in 1988. In 1988/89, 678 adults completed a dietary survey (85% of those eligible) and 248 adults participated again in 1995/96 (66% of those eligible). RESULTS: Energy intakes declined longitudinally in men only; however, this decline appeared not to be an aging effect as energy intake was not found to decrease with age cross-sectionally. Percentage of energy from protein increased by 0.7% in women (95% confidence interval 0.2-1.2) in both the longitudinal and time-sequential analysis, suggesting a time effect. The percentage of energy from saturated fat decreased 0.7% (95% confidence interval -1.4 to -0.1) and percentage of energy from polyunsaturated fat increased 0.4% (95% confidence interval 0.0-0.7) in women, and appears to be a time effect. However, the increase in saturated fat and decrease in polyunsaturated fat with advancing age seen cross-sectionally suggests a cohort effect also occurring. In 1995/96, more people were using margarine as a spread and vegetable oils to cook meat. Milk and milk product consumption increased (not significantly), and meat intake decreased significantly by 5 and 4 servings per month in men and women, respectively. There was an increase in the proportion of people who ate breakfast cereal at least once a week, and more women ate brown or wholemeal bread in 1995/96. CONCLUSION: Over the 6 y follow-up period studied, there was no indication of an age effect on nutrient intakes in adults aged 70 y and older; however, the changes occurring over time demonstrate that older adults, particularly women, are making changes towards healthier food choices.

Attention is needed to the high prevalence of vitamin D deficiency in our older population.

The aim of this study was to assess the prevalence of vitamin D deficiency in females residing in one large, aged-care facility in Auckland. Thirty-nine residents, most of whom were able to go outdoors without assistance, were tested for midwinter 25-hydroxyvitamin D, and, of these, 36 were tested again in midsummer. The prevalence of frank hypovitaminosis (<10 microg/L) was found to be 49% in midwinter and 33% in midsummer. The vitamin D status of such at-risk individuals could be normalised either by 15-30 minutes of daily sun exposure or, alternatively, a programme of supplementation.

Applying the transtheoretical model to eating behaviour change: challenges and opportunities.

This review provides a rigorous investigation of the question of whether the transtheoretical model (TTM) (or stages of change model) is applicable to eating behaviour change. The TTM is currently the most popular of a number of stage theories being used to examine health behaviour change. Stage theories specify an ordered set of 'stages of readiness to change' into which people can be classified and identify the factors that can facilitate movement from one stage to the next. If eating behaviour change follows a stage process, then nutritionists could identify the predominant stage or stages in a population and focus resources on those issues most likely to move people to the next stage (e.g. from no intention of changing, to thinking about changing). In addressing this question, the review draws on the defining characteristics of stage theories as clarified by Weinstein et al. (1998), provides an in-depth coverage of methodological considerations, and a detailed summary table of dietary studies applying the TTM. Specific recommendations are made for improving the accuracy of dietary stage classifications. Among the key conclusions are: (1) dietary studies using the TTM have been hampered by a focus on nutritional outcomes such as dietary fat reduction, rather than clearly understood food behaviours (e.g. five servings of fruit and vegetables per day); (2) accurate stage classification systems are possible for food-based goals, but major misclassification problems occur with nutrient-based goals; (3) observation of an association between stage and dietary intake is not sufficient to demonstrate the validity of the model for dietary behaviour; (4) there is a need for valid questionnaires to measure all aspects of the TTM, and more research on the whole model, particularly the 'processes of change', rather than on single constructs such as 'stage' (5) cross-sectional studies generally support the predicted patterns of between-stage differences in decisional balance, self-efficacy, and processes of change; (6) studies which test the key hypothesis that different factors are important in distinguishing different stages are rare, as are prospective studies and stage-matched interventions. Only such studies can conclusively determine whether the TTM is applicable to eating behaviour. Since the ultimate test of the TTM will be the effectiveness of stage-matched dietary interventions, the review ends by exploring the requirements for such studies.

Control over future health in old age: characteristics of believers and sceptics.

In a cross-sectional study of a total population aged 70 years and over in a rural New Zealand township (sample size 682) we investigated factors which characterize those who felt they had a great deal of control and those who felt they had little or no control over future health. In a significant logistic regression model those with a feeling of a great deal of control over future health had a lower prevalence of chronic obstructive lung disease, higher prevalence of diabetes, took less alcohol, were more likely to be satisfied with bowel function, had a lower protein intake, were more likely to participate in strenuous to moderate activity and were less likely to have features of depression. Different perceptions of control were associated with significant differences in health practices and health status.

Relation of age, exercise, anthropometric measurements, and diet with glucose and insulin levels in a population aged 70 years and over.

A community-based sample of people > or = 70 years from Mosgiel, New Zealand, was investigated to determine the relation of age, diet, exercise, drugs, and anthropometric measurements with glucose and insulin. From an initial sample of 856 subjects on August 1, 1988, 782 (91.4%) completed the questionnaires and physical examination. Glucose was estimated in 726 subjects and insulin in 607 subjects 2 hours after a standardized meal. In the multivariate analysis for women, glucose was related to age and exercise, and insulin was related to glucose levels, triceps skinfold thickness, and waist/hip ratios. In the multivariate analysis for men, none of the variables was related to glucose levels; insulin levels were related to glucose and waist/hip ratio. Impaired glucose tolerance in women was associated with high body mass index, waist/hip ratio, lower exercise levels, and the taking of thiazide drugs or oral steroids. In men, no significant model to identify those with impaired glucose tolerance could be developed. Glucose and insulin levels in women were related to age and external factors, particularly exercise and anthropometric measurements. In men, external factors were less clearly related to glucose and insulin levels, but this lack of association in men may be due to the smaller number of men in the sample, their younger age, and the narrower range of values found in the men.

Validity of a short food frequency questionnaire for estimating nutrient intake in elderly people.

Nutrient intakes estimated using a short self-administered semi-quantitative food frequency questionnaire (FFQ) were compared with results obtained from five 2 d diet records using household measures in a group of fifty-three elderly people (mean age 70 years) in Dunedin, New Zealand in 1989. Mean intakes for most nutrients were less than 5% different between the two methods. Correlations between the nutrient intake values (excluding supplements) from the diet records and those from the FFQ ranged from 0.34 for Zn in women to more than 0.75 for protein, Zn and Ca in men. For most nutrients, at least 70% of the subjects when classified by the food records fell into the same quintile or into the within-one-quintile category when classified by the FFQ. These data indicate that in elderly subjects a simple self-administered semi-quantitative FFQ can provide very similar information (for both group and individual intakes for many nutrients) to that obtained from 10 d of careful diet recording.

Factors associated with constipation in a community based sample of people aged 70 years and over.

STUDY OBJECTIVE: The aim was to determine the prevalence and factors associated with constipation in elderly people. DESIGN: The study was a survey involving administration of a structured questionnaire, an interview, and a dietary assessment. SETTING: The survey was community based and the population studied was drawn from the practice records of all five general practitioners serving a rural township of 13,500 people. PARTICIPANTS: 778 (91.8%) of the 856 people aged 70 years and over registered with the five practitioners took part. MAIN RESULTS: 174 subjects had symptoms of infrequent bowel motions or frequent straining at stool or used laxatives regularly. Of this group, 34 had a bowel motion only every 3 d or less frequently and were considered to have constipation. Analysis of this subgroup showed that constipation was more common in women than men, increased with age, and was associated with the use of constipating drugs. Those whose bowels moved infrequently were a more frail group who were less physically active. Low intakes of dietary fibre, fruit, vegetables, bread and cereals, or fluid were not associated with an increased occurrence of constipation. There were 151 subjects who felt they were moderately constipated, but who had a bowel motion at least every 2 d. These people were more likely than the rest of the sample to use laxatives (55.6%), were more likely to take food for their bowels, to take hynoptics, and to regard their health as poor. CONCLUSIONS: About one third of people aged 70 years and over have some bowel problem such as infrequency, straining at stool, or frequent laxative use. Most modify their diet accordingly but laxative use remains high.

Dietary changes reported by a random sample of elderly people.

A random sub-sample of 153 elderly people was followed up 18 months after a large-scale random dietary survey of adults aged 65 years and over residing in Adelaide, South Australia. The follow-up questionnaire examined self-reported dietary and weight change over the 18 month period since the original study. The same semi-quantitative food frequency questionnaire as used in the initial survey was also repeated. Challenging the common stereotype of rigidity and resistance to change in elderly people, a high degree of dietary change was reported since the original study (67% of men and 68% of women reported a change in diet), particularly among the 65-69 year age group (78%). The most commonly reported changes were largely in accord with dietary guidelines. Commonly reported changes included less frequent intake of red meat, eggs, fried and fatty foods and more frequent intake of vegetables, chicken and fish, as well as changes towards use of polyunsaturated margarine, no longer eating the fat on meat and no longer presoaking vegetables in water before cooking. Of concern was a change in some subjects to a less frequent consumption of milk or other dairy products.

Nutrition goals for older adults: a review.

Elderly people are generally identified as being at particular risk of poor dietary intake and nutritional problems and are thus a high-priority target group for nutrition education. In this paper, specific goals of nutrition education for older adults and high-risk groups within the elderly population are discussed through a review of three crucial areas: (1) current knowledge of the eating patterns, nutrient intake, and supplement use of older adults; (2) existing information on the multiple influences (physical, behavioral, and socioeconomic) on the eating habits of older adults; and (3) the potential benefits and likely efficacy of dietary and life-style changes in this age group.

Dietary habits of elderly persons with diabetes.

The dietary habits and nutrient intakes of a group of 151 persons with diabetes were compared with those of a group without diabetes in a random postal survey of 3,000 individuals aged 65 years and older residing in Adelaide, South Australia. A semiquantitative food frequency questionnaire was used. The response rate was 77%. Only 64% of individuals with diabetes reported following a diabetic diet at the time of the survey, and only 6% were consuming a high-carbohydrate, low-fat diet (greater than or equal to 50% energy intake from carbohydrate and less than or equal to 30% from fat). The dietary habits of elderly persons with diabetes suggested an awareness of the need to limit simple sugars; however, adherence to the latest recommendations concerning dietary fat and fiber was poor. Individuals with diabetes had lower intakes of refined carbohydrate but were just as likely as those without diabetes to eat high-fat foods, and they ate eggs and cheese more frequently. Those with diabetes were no more likely than those without diabetes to consume the recommended complex-carbohydrate and fiber-rich foods. The extent of adherence to current dietary recommendations for the management of diabetes was found to be independent of sex, age, occupational status, educational attainment, marital status, living arrangements (alone vs with a spouse), and source of income.

Assessment of the validity of a food frequency questionnaire as a measure of food use by comparison with direct observation of domestic food stores.

The aim of this study was to assess the validity as a measure of food use of a 90-item semi-quantitative food frequency questionnaire which had been used in a study of food consumption patterns and health among 3,000 people aged 65 years and over selected at random from the electoral rolls of Adelaide, South Australia. In 1986, 18 months after the original survey, 200 randomly selected participants were invited to take part in the present study. The food frequency questionnaire was administered by mail, and results were compared with a direct observation of the foods that 40 subjects had in their home. The kappa statistic indicated good agreement (in all cases greater than that expected due to chance) between the reported use of individual foods in the questionnaire and the observed presence or absence of those foods in the subject's home. Correlation coefficients between scores generated from the questionnaire for consumption from specific food groups and those derived from direct observation of domestic food stores ranged from 0.42 to 0.86. These data indicate that a simple self-administered dietary questionnaire can provide a valid measure of food use patterns in elderly people.

Dietary supplement use in a randomly selected group of elderly Australians. Results from a large nutrition and health survey.

The prevalence of dietary supplementation and its relationship to health and dietary habits was investigated in a random mail survey of 2,195 people aged 65 years and over in Adelaide, South Australia. Subjects were selected from the electoral rolls in an urban area, and 77% returned completed survey instruments. Thirty-five percent of men and 46% of women reported taking some form of supplement at least once a week regularly throughout the year (these are defined as "regular" supplementers). The most popular supplements (in descending order of popularity for the total group) were: unprocessed bran, wheatgerm, vitamin C, and multivitamins or minerals. Thirteen percent of men and 15% of women reported the use of supplements on an occasional basis (once every few months or "now and then")--these are defined as "irregular" or "occasional" supplementers. Supplement users did not differ from non-supplementers in their use of medical facilities or in the number of bouts of minor illness they had experienced in the preceding year. Regular supplement users had more favorable dietary habits and higher intakes of several vitamins, minerals, trace elements and fiber than either non-supplementers or occasional supplementers.

Chewing difficulty and dietary intake in the elderly.

Dietary intake and self-assessed chewing difficulty were examined in a postal survey of a random sample of 1000 people aged 65 years and over residing in Adelaide, South Australia, by means of a semi-quantitative food frequency questionnaire. The response rate was 77 per cent. Fourteen per cent of the respondents reported poorly fitting dentures, and of these 35% reported difficulty in chewing. Dietary intake was largely independent of self-assessed chewing difficulty, although among women loss of chewing efficiency was associated with preference for sweet and soft foods. Dietary differences in people dissatisfied with their chewing ability appear likely to be subtle and qualitative (i.e., chopping hard foods into small pieces or cooking them for longer periods).