TABLE 3.

Controlled Studies of Testosterone Supplementation in Cognitively Normal Older Men with Low Testosterone

Authors, Year	N	Mean Age (Range)	Method of T Measurement	Baseline T Level	Cognitive Measures*	Supplementation Method	Significant Conclusions
Cherrier et al, 2003	12	57 (34–70)	Morning TT	TT < 300 ng/dL	MEM 4, 19 VS 7, 13 ATT 3	T gel 50 or 100 mg/day for 180 days	Improvement in MEM 4 with T
Kenny et al, 2002	67	76 (65–87)	TT, BT	BT < 128 ng/dL	MEM 1, 2 ATT 4, 5	T transdermally 5 mg/day for 1 year	Improvement in ATT 5 with T
Sih et al, 1997	32	68 (51–79)	TT, BT	BT < 60 ng/dL	MEM 8, 9, 10, 11	T cypionate intramuscularly 200 mg every 14–17 days for 1 year	No significant differences in any tests with T
Vaughan et al, 2007	69	70.8 (65–83)	Morning TT, BT, DHT	TT < 350 ng/dL	MEM 1, 12, 14 VS 2 ATT 4, 5	T enanthate intramuscularly 200 mg every 2 weeks (± finasteride) for 3 years	Improvement in MEM 1 with T, and in MEM 14 with T + finasteride

^*Table 1 explains the abbreviated cognitive domains and the numbered cognitive tests.

T = testosterone. TT = total testosterone. BT = bioavailable testosterone. DHT = dihydrotestosterone.