 |
|
|
| |
Prior Meth Use Tied to Worse Neurocognitive
Function in Older But Not Younger HIV+
|
| |
| |
4th International Workshop on HIV and Aging, October 30-31, 2013, Baltimore
Mark Mascolini
Prior methamphetamine use portends worse neurocognitive function in older but not younger people with HIV infection, according to results of a six-way comparative study at the University of California, San Diego [1]. The earlier older study participants started using meth, the worse their neurocognitive function in older age.
About one quarter of HIV-positive people in the US CHARTER cohort have used methamphetamine, according to Steven Paul Woods, a UCSD psychiatrist [1]. Rates are even higher in West Coast cohorts, reaching a prevalence of 60% at UCSD. But methamphetamine use decreases with older age in HIV-positive people, CHARTER findings indicate. And people can recover from meth-induced neurotoxicity with extended abstinence from this potent and addictive psychostimulant.
To explore the impact of methamphetamine on cognitive function in older and younger people with or without HIV infection, Woods and colleagues studied three groups 50 and older and three groups 40 or younger. Each age group had subsets with or without a history of methamphetamine dependence and with or without HIV infection:
50 and older
36 HIV-/M-
49 HIV+/M-
31 HIV+/MA+
40 and younger
28 HIV-/M-
34 HIV+/M-
34 HIV+/M+
The UCSD team excluded people with a current diagnosis of alcohol abuse or nonmeth illicit substance use, a verbal IQ estimate below 70, or a history of potentially confounding major medical, neurologic, or psychiatric conditions.
In the older groups, age averaged 57.1 in HIV-/M- people, 57.3 in HIV+/M- people, and 53.9 in HIV+M+ people (P < 0.05). Respective proportions of Caucasians were 66.7%, 81.6%, and 71.0%, and respective proportions of men were 69.4%, 85.7%, and 80.7%. Compared with the HIV-/M- group and the HIV+/M- group, the HIV+/M+ group had a higher proportion with a long-term major depressive disorder (33.3% vs 51.0% vs 71.0%, P < 0.05). The HIV+/M+ group also had significantly higher proportions with long-term generalized anxiety disorder and long-term nonmeth substance abuse, but not long-term alcohol abuse.
Compared with younger HIV+/M+ people, older HIV+/M+ people got their first meth-dependence diagnosis at a later average age (34.7 vs 24.1, P < 0.05) and were older at their latest diagnosis (45.1 vs 31.3, P < 0.05). Average duration with a meth-dependence diagnosis was longer in older than younger HIV+/M+ people, but not significantly so (10.3 vs 7.2 years). In the older groups, average duration of HIV infection was longer in HIV+/M- people than HIV+/M+ people (20.5 vs 15.9, P < 0.05), and current CD4 count was higher in HIV+/M- people (584 vs 458.5, P < 0.05).
Among people 50 and older, global neurocognitive function was worse in HIV+/M- people than HIV-/M- people (P < 0.05), worse in HIV+/M+ people than in HIV-/M- people (P < 0.01), and worse in HIV+/M+ people than in HIV+/M- people (P < 0.05). In the 40-and-younger group, global function score was not significantly lower in the HIV+/M+ group than in the HIV-/M- group, but it was significantly lower in the HIV+/M- group than in the HIV-/M- group (P < 0.01).
In 50-and-older people, earlier onset of methamphetamine dependence was associated with worse global neurocognitive function (r = 0.40, P < 0.05). In this older group, HIV-positive people with methamphetamine dependence had significantly lower neurocognitive function scores than the HIV-/M- group for learning, memory, and attention (P < 0.01 for all comparisons).
Among people 50 and older, about 90% of HIV+/M+ people had impairment in one or more domains of daily functioning, compared with about 70% of HIV+/M- people (P < 0.05) and 45% of HIV-/M- people (P < 0.01). In the 40-and-younger group, about 60% of HIV+/M+ and HIV+/M- people had impairment in one or more domains of daily functioning, compared with about 30% of the HIV-/M- group (P < 0.01 for both comparisons). Methamphetamine use negatively affected basic activities of daily living, instrumental activities of daily living, employment, and cognitive symptom rates.
Between-group comparisons of the impact of methamphetamine were independent of cofactors such as demographics and depression, and within the older group the impact was independent of cofactors such as HCV coinfection and other substance use disorders.
Woods concluded that prior methamphetamine use affects neurocognitive and everyday function in older but not younger people with HIV. He proposed that this persisting impact of methamphetamine may represent a "legacy effect" of meth-associated neurotoxicity.
Reference
1. Woods S. Methamphetamine, HIV, and aging. 4th International Workshop on HIV and Aging, October 30-31, 2013, Baltimore. Invited lecture.
|
| |
|
|
|
|
|
