Assessment of Dietary Intake in Three Cohorts of Advanced Age in Two Countries: Methodology Challenges

OBJECTIVES

Dietary intake information is key to understanding nutrition-related outcomes. Intake changes with age and some older people are at increased risk of malnutrition. Application, difficulties, and advantages of the 24-hour multiple pass recall (24hr-MPR) dietary assessment method in three cohorts of advanced age in the United Kingdom (UK) and New Zealand (NZ) is described.

PARTICIPANTS

The Newcastle 85+ study (UK) recruited a single year birth cohort of people aged 85 years during 2006-7. LiLACS NZ recruited a 10-year birth cohort of Māori (indigenous New Zealanders) aged 80-90 years and a single year birth cohort of non-Māori aged 85 years in 2010.

MEASUREMENTS

Two 24hr-MPR were conducted on non-consecutive days by trained assessors. Pictorial resources and language were adapted for the New Zealand and Māori contexts. Detailed methods are described.

RESULTS

In the Newcastle 85+ study, 805 (93%) participants consented to the 24-MPR, 95% of whom completed two 24hr-MPR; in LiLACS NZ, 218 (82%) consented and 203 (76%) Māori and 353 (90%) non-Māori completed two 24hr-MPR. Mean time to complete each 24hr-MPR was 22 minutes in the Newcastle 85+ study, and 45 minutes for Māori and 39 minutes for non-Māori in LiLACS NZ. Dietary assessment of participants residing in residential care and those requiring proxy respondents were successfully included in both studies. Most participants (83-94%) felt that data captured by the 24hr-MPR reflected their usual dietary intake.

CONCLUSIONS

Dietary assessment using 24hr-MPR was successful in capturing detailed dietary data including information on portion size and time of eating for over 1300 octogenarians in the UK and New Zealand (Māori and non- Māori). The 24hr-MPR is an acceptable method of dietary assessment in this age group.

A gerophysiology perspective on healthy ageing

Improvements in public health and health care have resulted in significant increases in lifespan globally, but also in a significant increase in chronic disease prevalence. This has led to a focus on healthy ageing bringing a shift from a pathology-centered to an intrinsic capacity and function-centered view. In parallel, the emerging field of geroscience has promoted the exploration of the biomolecular drivers of ageing towards a transverse vision by proposing an integrated set of molecular hallmarks. In this review, we propose to take a step further in this direction, highlighting a gerophysiological perspective that considers the notion of homeostasis/allostasis relating to robustness/fragility respectively. While robustness is associated with homeostasis achieved by an optimal structure/function relationship in all organs, successive repair processes occurring after daily injuries and infections result in accumulation of scar healing leading to progressive tissue degeneration, allostasis and frailty. Considering biological ageing as the accumulation of scarring at the level of the whole organism emphasizes three transverse and shared elements in the body - mesenchymal stroma cells/immunity/metabolism (SIM). This SIM tryptich drives tissue and organ fate to regulate the age-related evolution of body functions. It provides the basis of a gerophysiology perspective, possibly representing a better way to decipher healthy ageing, not only by defining a composite biomarker(s) but also by developing new preventive/curative strategies.

Fluoroquinolone use in a rural practice

Introduction

Fluoroquinolones (FQs) are a commonly prescribed class of antibiotics in Canada. Evidence of a constellation of possible adverse events is developing. Central and peripheral nervous system abnormalities and collagen-related events (including aortic aneurysm/dissection, tendinopathy/rupture and retinal detachment) are associated with FQ exposure in large population-based aftermarket studies. In 2017, Health Canada warned about rare FQ-related persistent or disabling side effects. This study explores FQ use in a rural community.

Methods

Antibiotic prescriptions (including FQs) in the over 18 adult population (5416) were measured in the town of Sioux Lookout for 5 years, January 2013 to 31 December 2017.

Results

FQ prescriptions accounted for 16.0% of adult antibiotics, superseded by penicillins (21.1%) and macrolides (18.2%). Ciprofloxacin accounted for one half of FQ use (51.2%), followed by levofloxacin (36.7%) and norfloxacin (13.3%). FQs were commonly used for respiratory (33%) and urinary tract infections (18%).

Conclusion

Aftermarket evidence reports increased risk of 'disabling and persistent serious adverse events'(Health Canada) in patients using FQs. Appropriate clinical caution should be exercised in the prescribing of FQs. Common overuse seems to occur in the treatment of uncomplicated community-acquired pneumonia and cystitis, despite recommendations to use other antimicrobial agents as first-line treatments.

Muscarinic stimulation of the mouse isolated whole bladder: physiological responses in young and ageing mice

1 Peripheral autonomous bladder activity is an incompletely understood property that may be important both in normal bladder function and in functional problems of the lower urinary tract. We describe how a muscarinic agonist, arecaidine, influences intravesical pressure and intramural bladder contractions in the isolated mouse and how response varies in ageing mice. 2 A group of 12 mice aged 3-4 months was compared with an 'ageing' group of 12 mice age 28-34 months. Bladders were microsurgically removed and mounted in whole organ tissue baths. The effects of the muscarinic agonist arecaidine on intravesical pressure and intramural contractions were performed at different bladder volumes. 3 In normal mice, arecaidine elicited tonic and phasic contractions, the latter showing a more substantial increase in amplitude with bladder distension. Localized 'micromotion' contractions were seen in the bladder wall, with regional differences arising after exposure to arecaidine. A background release of acetylcholine was inferred from the pressure increase induced by the cholinesterase inhibitor physostigmine. 4 Both micromotion activity and the phasic component of the arecaidine response were substantially reduced in ageing mice; the tonic component was preserved in the same specimens. 5 We conclude that the enhanced pressure fluctuations seen at high bladder volumes may act as a peripheral determinant of bladder capacity, and that changes in such activity may contribute to altered functional capacity and lower urinary tract symptoms in ageing individuals.

Prospects for the genetics of human longevity

Longevity varies between and within species. The existence of species-specific limit to human life-span and its partial heritability indicate the existence of genetic factors that influence the ageing process. Insight into the nature of these genetic factors is provided by evolutionary studies, notably the disposable soma theory, which suggests a central role of energy metabolism in determining life-span. Energy is important in two ways. First, the disposable soma theory indicates that the optimum energy investment in cell maintenance and repair processes will be tuned through natural selection to provide adequate, but not excessive, protection against random molecular damages (e.g. to DNA, proteins). All that is required is that the organism remains in a sound condition through its natural expectation of life in the wild environment, where accidents are the predominant cause of mortality. Secondly, energy is implicated because of the intrinsic vulnerability of mitochondria to damage that may interfere with the normal supply of energy to the cell via the oxidative phosphorylation pathways. Oxidative phosphorylation produces ATP, and as a by-product also produces highly reactive oxygen radicals that can damage many cell structures, including the mitochondria themselves. Several lines of evidence link, on the one hand, oxidative damage to cell ageing, and on the other hand, energy-dependent antioxidant defences to the preservation of cellular homeostasis, and hence, longevity. Models of cellular ageing in vitro allow direct investigation of mechanisms, such as oxidative damage, that contribute to limiting human life-span. The genetic substratum of inter-individual differences in longevity may be unraveled by a two-pronged reverse genetics approach: sibling pair analysis applied to nonagenarian and centenarian siblings, combined with association studies of centenarians, may lead to the identification of genetic influences upon human longevity. These studies have become practicable thanks to recent progress in human genome mapping, especially to the development of microsatellite markers and the integration of genetic and physical maps.

Fibronectin is expressed by astrocytes cultured from embryonic and early postnatal rat brain

In early primary cultures from newborn rat brain, few glial fibrillary acidic protein (GFAP)-positive glial cells expressed intracytoplasmic immunoreactivity for fibronectin. After the second week in culture, however, fibronectin was expressed by a distinct population of GFAP-positive flat astrocytes, irrespective of which brain region was studied. In cerebellar cultures, these cells were more abundant than in cortical or neostriatal cultures and often formed a major population of the GFAP-positive cells. The difference in fibronectin expression between cerebellum and the other areas studied was statistically significant. When cultures were started from 9-day-old postnatal rat brain, fibronectin-positive astrocytes appeared earlier than in those from newborn animals, in all areas studied. Further, especially in the case of cerebellum, the number of fibronectin-positive astrocytes increased as a function of time in culture. In cultures started from whole brains of 12-day-old rat embryos, fibronectin was expressed within 24 h in culture by all the cells with morphology of flat astrocytes, positive for vimentin but negative for GFAP. These results indicate that astrocytes cultured from newborn and early postnatal rat brain are a heterogeneous population of cells: depending on the brain region studied and also depending on the age of brain tissue or the time in culture, less than 1-60% of the GFAP-positive flat astrocytes expressed fibronectin. This, together with the fact that fibronectin was present in early embryonic brain cells in culture, suggests that fibronectin may be a prerequisite for the development or interactions of brain cells.