Testosterone profile in older men with Alzheimer's disease

Perfil dos níveis de testosterona em homens idosos portadores da doença de Alzheimer

Abstract

Evidence suggests low testosterone levels in Alzheimer's disease. Objectives: To compare testosterone levels between older men with and without Alzheimer's disease. Methods: Fourteen men with Alzheimer's disease were compared with twenty eight men without dementia. Demographic variables and clinical profiles were analyzed. Within fifteen days before or after the described evaluation, measures of total testosterone and Sex Hormone Binding Globulin (SHBG) were performed. Free testosterone level was calculated based on total testosterone and SHBG. Quantitative variables were analyzed using Student's t test or Kruskal-Wallis test, while qualitative variables were analyzed using chi-square or Fisher test. Results: Mean age in the Control and Alzheimer's disease groups were 72.0 (SD±4.8) years and 79.3(SD±5.9) years, respectively (p=0.001). Mean schooling between these two groups were 8.78 and (±5.86) years, respectively (p=0.022). There were no statistically significant differences between the two groups for testosterone levels, although a trend was observed for the Alzheimer's disease group to present lower levels than the control group (p=0.066). There was no direct correlation between free testosterone and age, although a trend was evident (p=0.068). Conclusions: There was no significant difference in testosterone between men with AD and those without dementia.

Key words:
testosterone; cognition; Alzheimer's disease.

Resumo

Evidências sugerem testosterona reduzida na doença de Alzheimer (DA). Objetivos: comparar níveis de testosterona entre homens idosos com doença de Alzheimer e sem demência. Métodos: Comparamos 14 indivíduos com doença de Alzheimer leve e moderada, provável e possível e 28 sem demência. Analisamos variáveis demográficas e perfil clínico. Em um período de quinze dias antes ou depois da avaliação clínica, foram realizadas coletas séricas de testosterona total e SHBG. Testosterona livre foi calculada baseada na testosterona total e SHBG. Variáveis quantitativas foram analisadas pelo teste T-Student (paramétricas) ou Kruskal-Wallis (não-paramétricas); variáveis qualitativas, pelo teste Qui-quadrado ou de Fisher. Resultados: Médias de idade nos grupos Controle e DA foram 72,0 (±4,8) e 79,3 (±5,9) anos, respectivamente (p=0,001). Médias de escolaridade entre os grupos foram de 8.78 e 5.86 anos, respectivamente (p=0,022). Não houve diferença estatisticamente significativa entre os níveis de testosterona livre nos dois grupos, embora se observasse uma tendência do grupo DA a apresentar níveis menores que o controle (p=0,066). Não houve correlação direta entre testosterona livre e idade, embora seja possível observar uma tendência (p=0,068). Conclusões: não houve diferença significativa quanto aos níveis de testosterona entre indivíduos com DA e sem demência.

Palavras-chave:
testosterona; cognição; doença de Alzheimer.

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

References

• ¹
  Freitas EV, Py L, Cançado FAX, Doll J, Gorzoni ML, editores. Tratado de Geriatria e Gerontologia. 2a ed. Rio de Janeiro, Guanabara Koogan; 2006.
• ²
  Morley JE, Perry HM. Andropause: an old concept in new clothing. Clin Geriatr Med 2003;19:5001-5006.
• ³
  Kaufman JM, Vermeulen A. The decline of androgen levels in elderly men and its clinical and therapeutic implications. Endocr Rev 2005;26:833-876.
• ⁴
  Harman SM, Metter EJ, Tobin JD, et al. Longitudinal effects of aging on serum total and free testosterone levels in healthy men. J Clin Endocrinol Metab 2001;86:724-731.
• ⁵
  Beauchet O. Testosterone and cognitive function: current clinical evidence of a relationship. Eur J Endocrinol 2006;155:773-781.
• ⁶
  Bialek M, Zaremba P, Borowicz KK et al. Neuroprotective role of testosterone in the nervous system. Pol J Pharmacol 2004;56:509-518.
• ⁷
  Moffat SD, Zonderman AB, Metter EJ, et al. Free testosterone and risk for Alzheimer disease in older men. Neurology 2004;62:188-193.
• ⁸
  Pennanen C, Laakso MP, Kivipelto M, et al. Serum testosterone in males with Alzheimer´s disease. J Neuroendocrinol 2004;16:95-98.
• ⁹
  Morris JC. The clinical dementia rating (CDR): current version and scoring rules. Neurology 1993;43: 2412-2414.
• ¹⁰
  Costa LL, Magaldi RM, Gândara MER, et al. Prevalence of hearing impairment in patients with mild cognitive impairment. Dement Neuropsiychol 2007;3:253-259.
• ¹¹
  Hogervorst E, Williams J, Budge M, et al. Serum total testosterone is lower in men with Alzheimer's disease. Neuro Endocrinol Lett 2001;22:163-168.
• ¹²
  Suravarapu SMD, Bergstralh EJ, Farmer A, et al. Dementia and low testosterone and bioavailable testosterone levels in men. Alzheimer Dis Assoc Disord 2006;3: 138-140.

Publication Dates

• Publication in this collection
  Oct-Dec 2008

History

• Received
  28 Oct 2008
• Accepted
  20 Nov 2008