Vitamin B12 and homocysteine levels and 6-year change in peripheral nerve function and neurological signs.

BACKGROUND: Low vitamin B12 and high homocysteine (Hcy) levels are common in older adults and may be associated with worse neurological function. The aim of this study is to determine whether changes in B12 or Hcy levels are associated with longitudinal changes in peripheral nerve function and clinical neurological signs and symptoms. METHODS: Participants aged 60 years and older at baseline (n = 678; 72.2 ± 6.2 years; 43.5% male) were from the InCHIANTI Study. Low B12 (<260 pmol/L) and high Hcy (≥13 µmol/L) were measured at baseline and 3-year follow-up. Neurological function was assessed by peroneal nerve conduction amplitude (compound motor action potential) and velocity, neurological examination, and peripheral neuropathy symptoms at baseline, 3-year, and 6-year follow-up. RESULTS: At baseline, 43.8% had low B12 levels and 58.6% had high Hcy levels. Over 6 years, 12.4% declined to poor compound motor action potential (<1 mV) and 42.1% declined to poor nerve conduction velocity (<40 m/s). In mixed models analyses, sustained high Hcy was associated with worse compound motor action potential compared with sustained normal Hcy (p = .04), adjusting for demographics, diabetes, and folate level. Participants whose Hcy level became high at follow-up were more likely to become unable to detect monofilament at 6-year follow-up compared with those with sustained normal Hcy (odds ratio: 5.4; 95% CI: 1.5-19.0), adjusting for demographics, diabetes, body mass index, and peripheral arterial disease. There was no association with vitamin B12 level or with symptoms. CONCLUSIONS: High Hcy may be associated with worse sensory and motor peripheral nerve function. Because poor nerve function has been associated with lower strength and physical performance, these results have important implications for disability in older adults.

Association between physical activity, physical performance, and inflammatory biomarkers in an elderly population: the InCHIANTI study.

BACKGROUND: Our aim was to determine the association between physical activity and physical performance, and inflammatory biomarkers in elderly persons. METHODS: One thousand four persons aged 65 years or more, participants in a cross-sectional population-based study, were included. Interviewers collected information on self-reported physical activity during the previous year. Moreover, 841 participants performed a 400-meter walking test to assess physical performance. Plasma concentrations of inflammatory biomarkers were determined. RESULTS: Compared to sedentary men, men practicing light and moderate-high physical activity had a significantly lower erythrocyte sedimentation rate (-0.33 and -0.40 mm/h; p =.023 and p =.006, respectively), fibrinogen level (-43 and -39 mg/dL; p =.001 and p =.004, respectively), and logarithm of C-reactive protein (CRP) (-0.43 and -0.73 mg/L; p =.025 and p <.001, respectively), whereas only those men practicing moderate-high physical activity had a significantly lower uric acid level (-0.57 mg/dL; p =.023), log(interleukin 6) levels (-0.33 pg/mL; p =.014), and log(tumor necrosis factor-alpha) (-0.31 pg/mL; p =.030). In women, those practicing light and moderate-high physical activity had significantly lower uric acid (-0.45 and -0.34 mg/dL; p =.001 and p =.039, respectively) and log(interleukin 6) levels (-0.18 and -0.30 pg/mL; p =.043 and p =.004, respectively); only those women practicing moderate-high physical activity had significantly lower log(CRP) (-0.31 mg/L; p =.020). In women, when the analysis was adjusted for body mass index, the association between physical activity and CRP was no longer significant. Similar findings were observed when we carried these analyses according to physical performance. CONCLUSIONS: Current physical activity practice and performance are associated with inflammatory biomarkers. A significant beneficial association is already observed with light physical activity practice and intermediate performance.

Diverse effect of inflammatory markers on insulin resistance and insulin-resistance syndrome in the elderly.

OBJECTIVES: To evaluate the potential association between different inflammatory markers and insulin resistance (IR), as well as insulin-resistance syndrome (IRS) in a large, population-based study of older, nondiabetic persons. DESIGN: Cross-sectional study. SETTING: Outpatient clinic in Greve in Chianti and Bagno a Ripoli (Italy). PARTICIPANTS: One thousand one hundred forty-six nondiabetic subjects ranging in age from 22 to 104. MEASUREMENTS: Anthropometric measurements; plasma fasting levels of glucose, insulin, and cholesterol (total, high-density lipoprotein, low-density lipoprotein); homeostasis model assessment to estimate degree of insulin resistance; tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), soluble IL-6 receptor (sIL-6R), interleukin receptor antagonist (IL-1ra), and C-reactive protein (CRP) plasma concentrations; diastolic, systolic, and mean arterial blood pressure; and echo-color-Doppler duplex scanning examination of carotid arteries. RESULTS: Insulin resistance correlated with age (r=0.102; P<.001) and plasma levels of TNF-alpha (r=0.082; P=.007), IL-1ra (r=0.147; P<.001), IL-6 (r=0.133; P<.001), sIL-6R (r=-0.156; P<.001), and CRP (r=0.83; P<.001). Subjects in the upper tertile of IR degree were older and had higher serum levels of TNF-alpha, IL-1ra, and IL-6 and lower levels of sIL-6R than subjects in the lowest tertile. Independent of age, sex, body mass index, waist-to-hip ratio, triglycerides, drug intake, diastolic blood pressure, smoking habit, and carotid atherosclerotic plaques, higher IL-6 (t=2.987; P=.003) serum concentrations were associated with higher IR, whereas sIL-6R levels (t=-5.651; P<.001) were associated with lower IR. Furthermore, IL-1ra concentrations (t=2.448; P=.015) were associated with IRS, and higher sIL-6R plasma levels continued to correlate negatively with IRS. CONCLUSION: Different inflammatory markers are associated with a diverse effect on IR and IRS in elderly nondiabetic subjects.

Dietary intake estimated using different methods in two Italian older populations.

Most of the tools used to assess nutritional intake in large epidemiological studies were originally developed to be used in young and middle-aged subjects and, therefore, their validity and reliability when employed in older subjects remain uncertain. We conducted this study to verify whether the questionnaire developed in the context of the European Prospective Investigation into Cancer and nutrition (EPIC) could be used to assess dietary intake in the participants of InCHIANTI, an epidemiological study of risk factors for disability in late life, performed in 633 men (78% aged, > or =65 years) and 802 women (81% aged, > or =65 years) randomly sampled from the general population. In particular, the aim of this project was to collect preliminary information that could support a future study of concurrent validity. Data on food consumption assessed using the EPIC questionnaire from the InCHIANTI participants were compared with those collected using a 7-day diary in the National Nutritional Investigation into Dietary Behavior (INN-CA), a study conducted in 15 Italian centres aimed at assessing Italian households' and individuals' dietary intake. In spite of different populations and different methods used in data collection, the distributions of dietary intake from the two studies were remarkably similar for most macro- and micro-nutrients, both in men and women and according to age groups. At a population level, a food frequency questionnaire and a costly and time-consuming objective method provided similar estimates of dietary intake. Future study should attempt to generalize these findings at an individual level by collecting data with both instruments in the same subjects.

Age and disability affect dietary intake.

The purpose of the study was to provide information on dietary intake in the InCHIANTI study population, a representative sample (n = 1453) of persons living in two towns of Tuscany (Italy), including a large number of old and very old individuals (79.5% >65 y old). We also investigated whether difficulties in nutrition-related activities were associated with inadequate intake of selected nutrients. The percentage of persons with an inadequate intake of nutrients according to Italian Recommended Nutrients Levels (LARN) was higher in the older age groups. Older persons tended to adapt their diets in response to individual functional difficulties, often leading to monotonous food consumption and, as a consequence, to inadequate nutrient intakes. Multiple logistic models were used to evaluate whether inadequate intake of selected nutrients could be predicted by nutrition-related difficulties. Reporting difficulties in three or more nutrition-related activities (chewing, self-feeding, shopping for basic necessities, carrying a shopping bag, cooking a warm meal, using fingers to grasp or handle) significantly increased the risk of inadequate intake of energy [odds ratio (OR) = 3.8, 95% CI = 1.9-7.8) and vitamin C (OR = 2.2, 95% CI = 1.2-4.2, after adjustment for energy intake). More attention to functional problems in the elderly population and the provision of formal or informal help to those who have difficulty in purchasing, processing and eating food may reduce, at least in part, the percentage of older persons with poor nutrition.