Cross-sectional analysis of testosterone therapies in hypopituitary men on stable pituitary hormone replacement

Population-based patterns of prescription androgen use, 1976-2008

PURPOSE

Prescription testosterone (T) has limited approved medical indications and is a controlled substance in Canada. Utilization studies in other Westernized countries have revealed sharp increases in T use in recent years. We examined medical use of androgens, including T, over a ≥30-year period among adult (18+) men in a population-based study set in a Canadian juridisdiction of universal health care.

METHODS

Analyses were based on data from electronic records of dispensed prescriptions during 1976-2008 in Saskatchewan, Canada. All formulations of androgens listed in the provincial formulary (oral and injectable) were included. We examined demographics of users, androgen types used, switching patterns, and trends in the annual rate of use over time.

RESULTS

There were 11 521 androgen users who were followed for an average of 11.8 years. Overall, 11 types of androgens were used, and there were 86 812 dispensing events. The mean age at first use was 56.4 years (median: 58). Men had 7.5 prescription dispensing events on average (median: 2). The most commonly used formulations were methyl-T (36.2% of users) followed by T-enanthate (32.5%), T-cypionate (22.3%), and T-undecanoate (20.0%). Most users (82%) did not switch among androgen types. The annual rate of use varied substantially over time, with a marked increase observed from 1994 to 1999 and a decrease from 2000 to 2008.

CONCLUSIONS

Androgen users were largely middle aged and had relatively few dispensings. We hypothesize that observed secular trends in androgen use may align with drug treatment pattern changes for erectile dysfunction, including the advent of phosphodiesterase type 5 inhibitors.

The pituitary gland and age-dependent regulation of body composition

CONTEXT

The prevalence of obesity is increased in hypopituitarism. In the general population, body mass index (BMI) and waist circumference increase with advancing age. It remains uncertain whether age-related changes in pituitary function contribute to the changes in body composition associated with advancing years.

OBJECTIVE

Our objective was to study the relationship between pituitary function, body composition, and age in a large cohort of patients with hypopituitarism and a matched reference population.

DESIGN, SETTING, AND PARTICIPANTS

A total of 3632 GH-deficient adults with hypopituitarism, adequately replaced with all pituitary hormones except for GH, from the prospective KIMS database (Pfizer International Metabolic Database) were included in present analysis. A random sample of the general population (3427 subjects) was used as reference. Patients and controls were grouped by gender in five age cohorts of 10 yr from 28 yr onward.

MAIN OUTCOME MEASURES

Differences in BMI and waist circumference were evaluated.

RESULTS

Patients had a significantly higher BMI and waist circumference than controls, with larger differences at younger age. With advancing age, an increase in BMI and waist circumference was seen in controls but was virtually absent in the patients with adult-onset GH deficiency and hypopituitarism.

CONCLUSION

Patients with hypopituitarism have more excess body fat than age-matched controls, especially in the youngest age groups. The normal increase in fat mass with advancing age is not seen in adult-onset GH-deficient hypopituitarism, suggesting a potential role for the normal pituitary gland as an age-dependent regulator of body composition in adult life.

Assessment of quality of life in adult patients with GH deficiency: KIMS contribution to clinical practice and pharmacoeconomic evaluations

Quality of life (QoL) has emerged as an important construct that has found numerous applications across healthcare-related fields, ranging from research and clinical evaluation of treatment effects to pharmacoeconomic evaluations and global healthcare policy. Impairment of QoL is one of the key clinical characteristics in adult GHD and has been extensively studied in the Pfizer International Metabolic Database (KIMS). We provide summarized evidence on GH treatment effects for both clinical and health economic applications based on the KIMS data. The primary focus is on those aspects of QoL research that cannot be investigated in the traditional clinical trial setting, such as specific patient subgroups, cross-country comparisons and long-term follow-up. First, the impact of age, gender, disease onset, primary aetiology, extent of hypopituitarism, previous radiotherapy and obesity on QoL before and during long-term GH replacement is discussed. Secondly, the studies on QoL in relation to country-specific normative values are reviewed. Finally, health economic data derived from KIMS including both burden of disease and utility assessment are evaluated. We conclude that the wide spectrum of analyses performed on the KIMS data allows for practical application of the results not only to research and clinical practice but also to health policy and global medical decision making.