At 1 year , letrozole resulted in higher LH ( L 6.1 2.5 vs A 3.2 1.7 IU/L ) and testosterone ( 1038 348 vs 536 216 ng/dL ) with lower estradiol ( 2.8 2.8 vs 5.6 2.9 pg/mL ) and IGF-1 ( 237 51 vs 331 79 ng/mL ) .