SUN-237 Higher Doses of Testosterone Gel Required in Hypogonadal Men with Obesity to Achieve Therapeutic Replacement - Advice on Dose Titration

Introduction: Testosterone (T) gel is one of the most widely used treatment options for hypogonadal men. Our clinical practice has shown that a great percentage of men achieve therapeutic T levels 3 weeks after the commencement of T gel. This achievement depends on the initiation dose of T gel which may be contingent on body composition primarily waist circumference (WC) as a marker of visceral obesity. Objectives: To determine whether hypogonadal men with WC≥102cm were required to be commenced at initiation on higher doses of T gel. To determine the time required to achieve therapeutic T levels (Tostran 2% gel v Testogel 1%). To look for other parameters which may help assess the initiation dose e.g. body weight, BMI. Methods: A cross-sectional study involving 300 hypogonadal men. 112 men were commenced on Tostran and 188 men on Testogel. The following were assessed: baseline WC and total T (TT) correlation, the initiation T dose and the time when therapeutic levels are achieved, the average starting dose achieving therapeutic T levels in obese (WC≥102) and non-obese (WC<102cm) men, correlation between T gel dose achieving therapeutic T levels and the quartiles of WC, BMI and body weight. Results: Baseline characteristics: mean age 62.3y; mean TT 7.4 nmol/l; WC 113.9cm, BMI 33.45, mean weight 102.4kg, starting T gel dose 51.4mg. There was a negative correlation between WC and TT (p=0.039). The majority of men were commenced on either 50mg (56.4%) or 60mg (21.8%) of T gel. 88.9% of men achieved therapeutic T levels (24.8% by 3 weeks, 56.2% by 3 months, 73.1% by 6 months, 89.3% by 12 months, 97.9% by 24 months). There wasn’t significant difference between Tostran and Testogel. When comparing obese and non-obese men, the average starting dose achieving therapeutic T levels at 3 months (48mg and 58mg, respectively) was trending towards statistical significance (p=0.065). T gel dose achieving therapeutic T levels was positively correlated to WC quartiles 1&4 + 2&4, BMI quartiles 1&2 + 1&4 + 3&4, and body weight quartiles 1&4. Conclusions: Our study, like other studies has shown that men with higher waist circumference, which is a surrogate marker of obesity and metabolic syndrome, have lower total testosterone levels. Testosterone gel which is commonly used in the treatment of hypogonadism is an effective way of hormone replacement. However, only half the number of patients achieve therapeutic levels by 6 months and some patients take up to 12-24 months to achieve therapeutic levels of testosterone. Our study demonstrates that higher doses of testosterone is required to achieve therapeutic levels in men with greater waist circumference, weight and BMI. We hence suggest differential initiation dose and titration regime for patients with varying degrees of obesity and metabolic syndrome to decrease the time taken to achieve therapeutic concentration of testosterone.