Did you see this? Seems to contradict what most of us do - that more frequent injections raise hematocrit.
Twice Weekly Dosing of Injectable Testosterone Associated with Increased Erythrocytosis
The most common dose-limiting adverse effect of testosterone (T) therapy (TTh) is erythrocytosis, which may increase the risk for thromboembolic complications. We sought to determine if the incidence of erythrocytosis, as defined by a hematocrit (Hct) > 52%, could be avoided by more frequent, lower dose T injections. A sample of 55 men using injectable T (cypionate or enanthate) at a single dose and frequency was selected for analysis from The Baylor Men’s Health Database. Age, T dose and frequency of administration, Hct and during of TTh were extracted. Groups were divided into 27 men on 200 mg T once weekly (QW) and 28 men on 80-160 mg of T twice a week (BIW). BIW dosing was initiated in men in whom hypogonadal symptoms returned prior to administration of their next dose. Maximum Hct was determined for each patient and the cohort mean of these maxima calculated. Mann-Whitney U analysis was used to compare differences between numerical variables. Mean (range) ages were 43.2 (27-63) years and 40.6 (27-62) years for the QW and BIW cohorts, respectively (p=0.36). Maximum Hct (Interquartile Range) for the QW cohort was 49.2 % (43.4, 54.6) with erythrocytosis occurring in 11% of these men. In contrast, a maximum Hct of 51.4 % (45.7, 56.9) was observed in the BIW cohort, with 29% of men developing erythrocytosis ((p=0.007) when comparing QW and BIW dosing). The time to developing erythrocytosis, defined as the number of days until maximum Hct while on testosterone, was comparable in both groups (p=0.18). More frequent dosing of injectable T is associated with a higher maximum Hct and a higher incidence of erythrocytosis, although the rate at which erythrocytosis develops does not vary with the frequency of T dosing. These data suggest that dosing frequency, rather than total T dose, is an important factor in development of erythrocytosis in men on injectable TTh. Work supported by industry: no.