S. Finch

Plasma total homocysteine in a representative sample of 972 British men and women aged 65 and over.

Objectives: To provide a reference range for plasma total homocysteine (tHcy), an independent risk factor for vascular disease, and to explore relationships with nutritional indices for people aged 65 y and over, in the UK National Diet and Nutrition Survey (NDNS). Design: The survey procedures described in the National Diet and Nutrition Survey Report (1997) included a health-and-lifestyle interview, a four-day weighed diet record, anthropometric and blood pressure measurements and a fasting blood sample for biochemical indices, including tHcy. Setting: Eighty randomly selected postcode sectors from mainland Britain during 1995–1996. Subjects: Of 2060 people interviewed, 1527 were visited by the nurse, 1276 gave a blood sample and 972 had tHcy measured. About 80% were in their own homes and the remainder were in nursing homes or similar institutions. Results: Significant cross-sectional relationships, both univariate and multivariate were found between tHcy and index concentrations of folate and vitamin B12 (P<0.0001), and between tHcy and plasma creatinine, urea, calcium, zinc, α1-antichymotrypsin, lutein and cysteine (P=0.013 to <0.0001). Dietary nutrient analyses showed an association with folate intake. tHcy was also correlated with age and with domicile (free-living or institution), with history of vascular disease and with use of four classes of drugs, two of which are prescribed for vascular diseases. There was a north-south gradient in tHcy (P=0.005), and also in food choices, blood micronutrient indices and vascular disease prevalence. Conclusions: The concentrations of tHcy found in this study provide a reference range for people aged 65 y and over, in mainland Britain. tHcy is a valuable functional index of micronutrient status and intakes for British people aged 65 y and over, which can assist the development of health-promotion strategies. Sponsorship: This study was part of the National Diet and Nutrition Survey of people aged 65 y and over, which was funded jointly by the Ministry of Agriculture, Fisheries and Food and the Department of Health, and conducted by Social Community Planning and Research in conjunction with the MRC Dunn Nutrition Unit. The authors acknowledge financial support for the study from the Department of Health, the European Commission and British Heart Foundation.

Visual acuity measurements in a national sample of British elderly people

BACKGROUND Despite the fact that visual function has an important role in the quality of life in later years, very few studies have measured visual acuity in population based nationwide samples of British elderly people. Such measurements were carried out in the context of the national diet and nutrition survey of people aged 65 years or over (NDNS). METHODS NDNS participants, who were living in 80 different randomly selected postcode areas of mainland Britain, were visited at their home by a nurse who measured visual acuity at 3 metres, using the Glasgow acuity card (GAC) method. In addition, a brief questionnaire related to ocular health was administered. RESULTS Visual acuity was measured in 1362 NDNS participants who were not classified as mentally impaired. Visual impairment (using the WHO low vision criteria) was measured in 195 (14.3%) subjects. Prevalence of visual impairment increased significantly with age (65–74 years 3.1%; 75–84 years 11.6%; 85+ years 35.5%, p<0.001 for trend). Impaired vision was more common in subjects living in a nursing home (odds ratio adjusted for age 2.59 (95% CI 2.23 to 2.96)) and in women (odds ratio adjusted for age 1.55 (95% CI 1.21 to 1.89)). 132 (9.7%) subjects had previously undergone cataract surgery and another 157 (11.5%) had been told that they currently had cataract. Vision improved 0.2 log units or more (at least one Snellen line) with the aid of a pinhole occluder in 289 subjects (21.2%). CONCLUSION Results of this nationwide, community based study confirm that problems with poor distance visual acuity exist in a substantial part of the elderly community, particularly in women and people living in nursing homes.

Gender differences in food and nutrient intakes and status indices from the National Diet and Nutrition Survey of people aged 65 years and over.

Objectives: To determine the patterns and possible explanations for gender differences in food choices, nutrient intakes and status indices, especially for micronutrients, in a representative sample of older people living in Britain, who participated in the National Diet and Nutrition Survey of people aged 65 y and over during 1994–95.Design: The Survey procedures included a health-and-lifestyle interview, a four-day weighed diet record, anthropometric measurements and a fasting blood sample for biochemical indices.Setting: Eighty randomly-selected postcode sectors from mainland Britain.Subjects: Of 1556 older people not living in institutions who were interviewed, 80% agreed to provide a complete four-day diet record and 63% agreed to give a blood sample for status index measurements.Interventions: None.Main result: The most highly significant gender differences in food choices were that women ate more butter, full-fat milk and certain beverages, cakes, apples, pears and bananas, whereas men ate more eggs, sugar, certain meat products and drank more alcoholic drinks, especially beer and lager. When adjusted for energy intakes, the younger women (65–79 y) had higher intakes than the younger men, of fat, retinol, vitamin C and calcium. The older women (80+y) had higher intakes than older men, of fat and vitamin E, but lower intakes of protein, zinc and β-carotene. The younger women had better status indices than the younger men: for α- and β-carotenes, β-cryptoxanthin and vitamin C. Women had higher plasma concentrations of cholesterol and HDL cholesterol, phosphate and copper, but lower indices of iron and vitamin D status, than men. These gender differences in status were not altered by inclusion of the corresponding nutrient intakes in the model.Conclusions: There are gender differences in food choices, in energy and nutrient intakes and in nutritional blood status indices in older British people, especially those aged 65–79 y. Some of the status differences are attenuated in the age group of 80 y and older, whereas others are enhanced. The relationships between the quantity and type of foods or nutrients consumed, and nutrient status, are complex. With respect to suspected risk and protective factors for vascular disease, women aged 65–79 y had significantly better status for plasma α-and β-carotene, ascorbate, HDL-cholesterol and homocysteine; but, in contrast, they had lower blood haemoglobin concentrations and higher concentrations of total and non-HDL-cholesterol.Sponsorship: The British National Diet and Nutrition Survey series is funded by the Ministry of Agriculture, Fisheries and Food and the Department of Health, and this survey was conducted by Social and Community Planning Research in conjunction with MRC Human Nutrition Research (formerly MRC Dunn Nutritional Laboratory).

Estimation of the use of dietary supplements in the National Diet and Nutrition Survey: People Aged 65 Years and Over. An observed paradox and a recommendation.

Objective: To compare the evidence derived from blood biochemical status indices with the evidence from a questionnaire and from a 4-day weighed dietary record of micronutrient supplement use in the British National Diet and Nutrition Survey (NDNS) of People Aged 65 Years and Over; to resolve some apparent incompatibility between nutrient intake and status estimates, and to recommend an approach towards supplement recording that should improve accuracy.Design: The survey procedures described in the National Diet and Nutrition Survey Report (1998) included a health-and-lifestyle questionnaire, a 4-day weighed diet record, and fasting blood and urine sample for biochemical indices, including a wide range of micronutrients.Setting: Eighty randomly selected postcode sectors from mainland Britain during 1994–1995.Subjects: Of 2060 people interviewed, 1467 provided a blood sample and 1217 provided both a blood sample, and a complete 4-day diet record. About 20% were living in institutions such as nursing homes, and the remainder were living in private households.Results: After assigning the subjects to four categories by the use of dietary supplements (A, those not taking supplements (by questionnaire or by the 4-day record); B, those taking supplements (excluding prescribed ones) by questionnaire only; C, those taking supplements by 4-day record only; and D, those taking supplements by both questionnaire and 4-day record), these categories were then compared with respect to estimated total nutrient intakes and blood biochemical indices. Those in category B had estimated (4-day) nutrient intakes (from foods and supplements) that were indistinguishable from those in category A, but had biochemical indices that indicated significantly higher dietary intakes of several vitamins.Conclusions and recommendation: The 4-day weighed intake record may not have identified all of the subjects who were regularly taking micronutrient supplements in amounts sufficient to improve their biochemical status. Because survey respondents may use supplements irregularly or change their usual patterns of supplement use during a period of intensive diet-recording, it is important to design a dietary instrument that will minimise this potential source of inaccuracy. We therefore recommend that population surveys in which an accurate estimate of micronutrient intakes is required, from supplements as well as from food, should record supplement use for a period longer than 4-days. It is likely that a better estimate of long-term intakes can be achieved by combining a 4-day weighed diet record with a structured recall or several weeks of diary records, which focus specifically on the use of supplements.Sponsorship: The study was part of the National Diet and Nutrition Survey of People Aged 65 Years and Over, which was funded jointly by the Ministry of Agriculture, Fisheries and Food and the Department of Health, and conducted by Social and Community Planning Research in conjunction with the MRC Dunn Nutrition Unit. The authors acknowledge additional financial support from the European Commission.