Frailty phenotype: a clinical marker of age acceleration in the older HIV-infected population

AIM

To evaluate the association between DNA methylation and frailty in the HIV-infected population and to investigate the usefulness of assessing frailty as a clinical marker to identify age acceleration.

METHODS

Frailty was assessed according to Fried's frailty phenotype. DNA methylation was analyzed in 10 frail patients, and compared with 10 robust control patients, all with HIV. Predicted age was inferred using the Weidner's formula. Age acceleration was assessed using the difference between predicted and chronological age.

RESULTS

HIV-infected frail patients had significantly higher biological predicted ages than chronological ages (mean acceleration: 10.3 years; p = 0.012).

CONCLUSIONS

We link age acceleration and frailty in an older HIV population. Frailty could be used in this population for implementing specific clinical approaches.

[HIV infection as a cause of accelerated aging and frailty]

The HIV-infected population is aging due to the success of combination antiretroviral therapy, which prolongs survival, as well as the growing number of newly diagnosed cases in adults 50 years old and over. HIV-infected individuals suffer from an accelerated aging due to the persistent and chronic activation of the immune system that leads to immune exhaustion and accelerated immunosenescence, even when on optimal immuno-virological control treatment. The clinical expression of the immunosenescence state is an increased prevalence of aging-related non-HIV associated comorbidities and a rising prevalence of frailty occurring earlier than in the general population. Thus, HIV-infected patients are biologically older than their chronological age, and they suffer from aging-related problems, such as frailty, which should be assessed.

Frailty and physical function in older HIV-infected adults

Background and Objectives

HIV patients have seen accelerated ageing. Our objective was to determine the prevalence of frailty, to evaluate factors associated with frailty and to evaluate physical function in older HIV-infected adults.

Design

this was a cross-sectional study.

Setting

outpatient clinics of two public university hospitals in Madrid (Spain).

Methods

frailty was defined according to the criteria of Fried: shrinking, weakness, poor endurance and energy, slowness and low physical activity level, being frail those who met at least three criteria, prefrail one or two criteria and robust when they met no criteria. Physical function was assessed using standardised methods.

Results

we evaluated 117 HIV-infected patients. Mean age was 61.3 ([standard deviation] 6.87) years. All patients were on antiretroviral therapy. Median current CD4+ T-cell count was 638 (144-1871) cells/μl, and median CD4/CD8 ratio was 0.79 (0.00-3.62). The prevalence of frailty was 15.4%, and that of prefrailty was 52.1%. In the multivariate analyses depressive symptoms (OR [95% CI], 9.20 [2.17-39.05]) and CD4/CD8 ratio (OR 0.11 [0.02-0.61]) were associated with frailty. Even though 100% of the patients were able to walk and perform basic activities of daily life independently, functional impairment was high (20% slow gait and 55% Short Physical Performance Battery ≤9).

Conclusions

HIV-infected patients aged ≥55 years have a high prevalence of frailty and a high burden of functional impairment. Optimal management of this population requires close collaboration between infectious diseases specialists and geriatricians.

Effects of intravenous cocaine administration on cerebellar Purkinje cell activity

The goal of the present study was to investigate the effects of intravenous cocaine administration on cerebellar Purkinje cell firing. Extracellular neuron activity was recorded and cells were locally excited with spaced microiontophoretic pulses of glutamate. Glutamate-evoked and spontaneous discharges were compared before and immediately following cocaine administration. Cocaine injections (1. 0 and 0.25 mg/kg, i.v.) induced a reversible suppression of both spontaneous activity and glutamate-evoked excitation. Procaine was ineffective in producing similar actions. Cocaine only inhibited glutamate-induced excitation in animals pre-treated with reserpine (5 mg/kg, i.p.). Propranolol injections (10 mg/kg, i.p.) were ineffective in blocking cocaine-induced inhibitions. Yohimbine (5 mg/kg, i.p.) pre-treatment abolished cocaine-induced suppressions of either spontaneous or glutamate-evoked excitation. Therefore, cocaine administration decreases Purkinje cell spontaneous and glutamate-evoked discharges by a mechanism involving alpha(2)-adrenoceptor activation. It is suggested that by changing the normal function of the cerebellum cocaine can produce drug-related alterations in overt behavior and cognition.

Effect of myotonia induced by anthracene-9-carboxylic acid on mitochondrial calcium, plasma creatinine-phosphokinase and aldolase activity in the rat

The frequent association of myotonia with dystrophy and the knowledge that calcium is increased in injured skeletal muscle cells suggest a possible relationship between cell calcium and myotonic alterations. This investigation has been performed to study the role of calcium in experimental myotonia induced by anthracene-9-carboxylic acid (9-AC) in rats treated with several regimens of food and exercise. Thirty-two rats were divided into 4 groups of 8 rats each, one control and 3 experimental groups. The treatments included caffeine plus exercise (group 2), and a calcium-rich diet (group 3); these procedures were designed to increase intracellular calcium; another group was treated with 9-AC as a myotonia-inducer (group 4). The treatment for all groups lasted 60 days. No significant differences in plasma sodium, potassium, chloride and calcium between control and experimental groups were observed. Whole muscle calcium in wet tissue samples did no change with any treatment. On the contrary, mitochondrial calcium showed a significantly higher concentration in group 3 and 4. CPK and aldolase activities in groups 1, 2 and 3 were similar; but in group 4 these enzyme activities were significantly higher (p less than 0.05). The electrical and mechanical responses were not altered in any rat with any experimental treatment. Our data suggest that myotonia is a predisposing factor for an altered mitochondrial calcium homeostasis in this model; in addition, the enzyme activities of CPK and aldolase were increased in the rats of group 4 implicating that myotonia is a crucial factor in the development of enzymatic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)