Dyslipoproteinemia in the Elderly: Should It Be Treated?

Statins for the primary prevention of cardiovascular events in older adults: a review of the evidence

BACKGROUND

Although statins have been demonstrated to be beneficial for secondary prevention in the elderly, their use for primary prevention has not been well described.

OBJECTIVE

In this review, we summarize data regarding the efficacy, safety, and current recommendations for statins for the primary prevention of cardiovascular events in older adults.

METHODS

This review is based on a computerized literature search of the PubMed database for articles published in the English language from January 1980 to June 2006. Key words searched individually and cross-referenced included: statins, HMG-CoA reductase inhibitors, cholesterol, elderly, aged, cardiovascular disease, primary prevention, risk stratification, and C-reactive protein. This search produced 445 citations; reference lists revealed an additional 12 citations, all of which were screened for relevance to the topic.

RESULTS

The existing evidence suggests, but does not confirm, benefit from the use of statins for primary prevention in the elderly subgroup (ie, those aged >65 years). Of the 6 published trials of statins for primary prevention, only 3 included subjects aged >75 years, and subgroup results in older adults are unavailable. Current guidelines recommend statins for individuals based on their assessed cardiovascular risk.

CONCLUSIONS

Extension of treatment guidelines should consider an individual's global risk of coronary heart disease. However, due to the prevalence of subclinical disease in older adults, risk may be higher or otherwise differ with age. In addition, tolerance for and barriers to adherence with long-term medical therapy are important treatment considerations in older adults. Prospective, randomized controlled trials that better define the tolerability, safety, and efficacy of statin therapy in older adults with elevated cholesterol levels and intermediate cardiovascular risk are needed.

Age-related changes in the hepatic sinusoidal endothelium impede lipoprotein transfer in the rat

The mechanisms for the association of old age with post-prandial hyperlipidemia and atherosclerosis are not well understood. Post-prandial hyperlipidemia has emerged as a significant risk for atherosclerosis. The liver is the central organ for lipoprotein metabolism. The initial step in the hepatic uptake of post-prandial lipoproteins is their transfer from the hepatic sinusoidal capillary lumen across the hepatic sinusoidal endothelium into the space of Disse. Here, they access hepatocytes for receptor-mediated uptake. We proposed that fenestrations (pores) within the hepatic sinusoidal endothelium filter lipoproteins on the basis of size. Recently we discovered age-related changes in the sinusoidal endothelium (pseudocapillarization), including reduction in the porosity of the endothelium. Using the impulse response technique in perfused rat livers, we found that aging is associated with impaired hepatic transendothelial transfer of chylomicrons with diameters smaller than those of fenestrations. In conclusion, age-related pseudocapillarization of the hepatic sinusoidal endothelium provides a novel mechanism for the association of old age with impaired hepatic lipoprotein metabolism and with atherosclerosis.

Hepatic pseudocapillarisation and atherosclerosis in ageing

Cardiovascular disease secondary to atherosclerosis is the main cause of death and disability in industrialised countries, and ageing is the foremost risk factor for atherosclerosis. We present a hypothesis linking age-specific structural change in the liver with accepted pathogenic mechanisms leading to atherosclerosis. Ageing in the liver is associated with pseudocapillarisation of the sinusoidal endothelium, which is characterised by thickening of endothelium, basement membrane formation, and defenestration (loss of pores). Fenestrations (pores) normally form a liver sieve that allows passage of chylomicron remnants for subsequent uptake and metabolism by hepatocytes. Ageing is associated with impaired clearance of chylomicron remnants, postprandial hypertriglyceridaemia, and hence, atherosclerosis, which we propose is linked directly to loss of permeability of the liver sieve because of defenestration associated with pseudocapillarisation. Development of methods to maintain fenestrations of sinusoidal endothelium or to facilitate refenestration might be a new therapeutic strategy for management of cardiovascular disease in old people.

Managing dyslipidemia in older adults

OBJECTIVES

To summarize and critically review clinical trial data regarding dyslipidemia as a risk factor for coronary heart disease (CHD) and the efficacy and safety of lipid-lowering interventions in older adults. Based on these data, clinical recommendations for diagnosing and managing dyslipidemia in older adults are provided.

METHODS

Peer-reviewed journal articles were identified by a MEDLINE search and a review of journal article references. Studies that were performed exclusively in subjects older than 65 years or that included a large subgroup of older adults were included.

CONCLUSIONS

Elevated low density lipoprotein and total cholesterol levels are independent risk factors for CHD events in patients aged older than 65 years. Older adults have a higher risk of mortality attributable to hypercholesterolemia. Diet and lipid-lowering medications safely and effectively lower cholesterol levels in this age group. Exercise increases high-density lipoprotein cholesterol levels and decreases triglyceride levels. If accompanied by weight loss, exercise may reduce low-density lipoprotein and total cholesterol levels. Improving lipid levels in older adults with CHD decreases the risk of future coronary events by up to 45%, and significant effects on outcome measures may be observed within 2 years of the initiation of therapy.

Medication use in residential care facilities for the elderly

OBJECTIVE

To describe medication use by residents of residential care facilities for the elderly (RCFEs).

DESIGN

A cross-sectional survey of medication use.

SETTING

Licensed, private RCFEs recruited from a roster of all licensed RCFEs in the Los Angeles area.

SUBJECTS

Residents who were > or =60 years of age and whose medications were centrally stored in the facility.

MEASURES

Age, gender, race, health insurance coverage, dietary restrictions, ambulation status, medical diagnoses, and medication profile.

RESULTS

A total of 818 residents were surveyed. Residents were primarily white women who were >80 years. The average number of medications per resident was five; 94% of the sample took at least one medication. Cardiovascular drugs, central nervous system drugs, analgesics, diuretics, and potassium supplements were most commonly used. Use of multiple drugs within a therapeutic class was also common, with means ranging from 1.46 to 1.81 per resident for the most commonly prescribed classes. Diagnoses supporting the use of many medications were not documented in the residents' health records.

CONCLUSIONS

This RCFE sample was medically frail and took many medications. The frequent use of cardiovascular medication reflected the prevalence of cardiac disease in the elderly. The frequency of psychotropic drug use without a corresponding indication suggested prescribing for symptoms rather than documented medical conditions. Lack of recorded diagnoses limited the ability to evaluate drug therapy. Improved record keeping; periodic medication review; and resident, staff, and prescriber education are necessary to ensure appropriate medication use in this setting.

Lipid screening in an elderly population: difficulty in interpretation and in detection of occult metabolic disease

AIMS

To determine lipid profiles and associations with other metabolic disease in a representative British elderly population.

METHODS

Part of a prevalence survey of dementia in all 75+ year olds conducted from the large general practice serving the town and surrounding area of Melton Mowbray, Leicestershire (the M-old study). Patients (n = 224) aged from 75 to 98 years, and representative of the overall population, also provided pre-prandial blood samples on which various age and nutrition related analytes were determined. These included documented medical history, thyroid stimulating hormone (TSH), glucose, immunoglobulins, and lipid profile in plasma.

RESULTS

Cholesterol and lipid variables showed wide scatter, with some negative trends but no significant associations with age for total cholesterol, high density lipoprotein (HDL) cholesterol, the ratio of total to HDL cholesterol or triglycerides. Women had significantly higher concentrations of total and HDL cholesterol at all ages. Serum TSH was above 6.0 mU/1 in 10/205 patients, random glucose was above 11.2 mmol/l in nine of 207 patients, borderline dysglobulinaemia was present in four of 210 patients, all without correlation with cholesterol concentrations.

CONCLUSION

This British data is consistent with an inverse correlation between survival and cholesterol, but wide scatter restricts reliance on single result lipid data in individual patient management. Random lipid screening is also unhelpful, inefficient and without added value in revealing other age related and unrecognised occult metabolic disease.