Compliance with growth hormone treatment--are they getting it?

Adherence to somatotropin treatment administered with an electronic device

INTRODUCTION

Adherence to somatotropin treatment is associated with increased growth velocity and improved adult height. The purpose of this study is to determine the adherence of patients undergoing treatment with an electronic device and its relationship with different variables (age, gender, duration of treatment, diagnosis, height, and growth rate).

MATERIAL AND METHODS

Descriptive, longitudinal and retrospective study of children less than 14 years of age undergoing treatment with somatotropin administered with the Easypod® electronic device in the Paediatric Endocrinology Outpatient Clinic of the General University Hospital of Ciudad Real, Spain. Adherence was monitored for 12 months and was defined according to the equation: (days administered at the prescribed dose / prescribed days)×100. The data analysis was performed using SPSS software.

RESULTS

Data were collected from 30 patients, with a predominance of males (57%), a mean age of 6.09 years, with 51% of children less than 5 years old. The most common reasons for the treatment were: small for gestational age (55%) and growth hormone deficiency (38%). The mean duration of treatment was 4.3 years (3.6-5). A mean adherence of 92.3% (87.7-96.9) was observed, and there was a significant correlation with age (Pearson R = -0.384, P=.03), and duration of treatment (Pearson R = -0.537; P=.003).

CONCLUSIONS

The adherence in our patients with electronic device is high (92.3%), and is inversely associated with age and duration. The use of electronic devices allows monitoring of therapeutic compliance, which affects the optimisation of treatment.

Adherence to growth hormone therapy in children and its potential barriers

BACKGROUND

One of the main concerns in chronic diseases such as growth hormone (GH) deficiency is adherence to the treatment, which significantly affects treatment outcomes.

METHODS

This cross-sectional study was conducted among 169 GH recipient children (2-12 years) and teens (13-19 years) referred to a GH distributing teaching pharmacy. The eight-item Morisky Medication Adherence Scale (MMAS) and auto-compliance method were used for the assessment of patients' adherence to GH. The potential barriers to GH therapy adherence and medication persistence were also explored.

RESULTS

Based on the MMAS method, 56.7% of the children and 57.9% of the adolescent groups were adherent to GH therapy. Conversely, according to the auto-compliance method almost all the patients were adherent in the children (95.2%) and adolescent (95.5%) groups. Forgetting to take the injection or refill the prescription, being away from home, exhaustion from long-term injection, drug shortage and inaccessibility to the pharmacy were barriers found to be significantly associated with a low adherence in the children group. While in the adolescent group, forgetting to take the injection, painful injection, concern about long-term complications and exhaustion from long-term injection revealed a significant association with low adherence. Persistence with GH therapy was reported in 75.3% and 67% of children and adolescent patients, respectively.

CONCLUSIONS

The current study revealed that overall adherence of the study population is low. Considering the barriers with significant association with adherence, different strategies can be incorporated to enhance adherence to GH therapy, i.e. providing early patient and parent education and support, medication reminder systems and longer duration of GH prescriptions.

Understanding the growth hormone therapy adherence paradigm: a systematic review

INTRODUCTION

Growth hormone (GH) therapy is used to treat a variety of growth disorders in childhood/adolescence. Its efficacy is thought to be dependent on patients' adherence to their treatment regimen.

METHODS

PubMed was searched using the keywords 'growth hormone', 'child'[Mesh], 'adolescent'[Mesh], and 'patient compliance'[Mesh].

RESULTS

Most studies of adherence to paediatric GH therapy have used either issued/encashed GH prescriptions or questionnaires. Estimates of prevalence of non-adherence vary from 5-82%, depending on the methods and definitions used. Different studies have variously demonstrated an association (or lack thereof) between adherence and age, socioeconomic status, treatment duration, injection device used and injection-giver. A number of interventions have been proposed to improve adherence, including offering a choice of injection device, but none are supported by trials. Poor adherence is associated with reduced height velocity and likely increased economic costs; evidence for other effects is circumstantial.

CONCLUSION

Adherence to paediatric GH therapy is suboptimal, which may partially explain why the mean final height attained is below that of the general population. Analysis of the causes of non-adherence is complicated by conflicting evidence from different studies. Multifactorial interventions are most likely to be successful in improving adherence. We make recommendations for further research.

Developing long-acting growth hormone formulations

Daily recombinant growth hormone (GH) restores normal growth and body composition in GH-deficient children and adults; however, daily injections are inconvenient and can be distressing for some children. On top of this compliance is a problem in up to 75% of children. Developing long-acting GH formulations has proved challenging, and questions remain regarding safety and efficacy. In this review, we focus on the rationale for generating long-acting GH agonists and the technologies being developed to deliver prolonged exposure to GH.

Characteristics of children with the best and poorest first- and second-year growth during rhGH therapy: data from 25 years of the Genentech national cooperative growth study (NCGS)

BACKGROUND

Models assessing characteristics contributing to response to recombinant human growth hormone (rhGH) response rarely address growth extremes in both years 1 and 2 or examine how children track from year to year. Using National Cooperative Growth Study (NCGS) data, we determined characteristics contributing to responsiveness to rhGH and the pattern of change from years 1 to 2.

PATIENTS AND METHODS

Height velocity standard deviation score (HV SDS) for 2 years for prepubertal children with idiopathic GH deficiency (IGHD) (n = 1899) and idiopathic short stature (ISS) (n = 1186) treated with similar doses for two years were computed. Group 1 = HV SDS < -1; 2 = HV SDS -1 to +1; 3 = HV SDS > +1.

RESULTS

For IGHD, mean age was 7.5 years and similar in all groups. Year 1 HV SDS was associated with greater body mass index (BMI) SDS, lower pre-treatment HV, baseline height SDS, greater target height SDS minus height SDS, and lower maximum stimulated GH (P <0.0001). Year 2, 172/271 (73%) in group 1 moved to either group 2 (n = 156) or 3 (n = 16). Year 2 HV SDS was associated with greater year 1 HV SDS (r = 0.045, P <0.0001), greater BMI SDS, taller parents and lower peak GH.For ISS, year 1 HV SDS was associated with greater BMI SDS and lower pre-treatment HV (P ≤0.0001). 109/169 (64%) in group 1 moved to group 2 (n = 90) or group 3 (n = 19). Greater year 2 HV SDS was related to year 1 HV SDS (r = 0.27, P <0.0001).

CONCLUSION

For IGHD, multiple characteristics contributed to best first-year response but for ISS, best first-year HV SDS was associated only with BMI SDS and inversely with pre-treatment HV. For both GHD and ISS, year 1 HV SDS was not a strong enough predictor of year 2 HV SDS to use first-year HV alone to determine GH continuation.

The impact of fasting and treatment omission on susceptibility to hypoglycaemia in children and adolescents with GH and cortisol insufficiency

OBJECTIVE

Hypoglycaemia may be a frequent occurrence in young GH deficient patients and so we studied the response to fasting in children and adolescents with GH and/or cortisol deficiency.

METHODS

A total of 20 patients (2-18 years) fasted for 14 h (22.00-12.00 h) on two occasions as part of a randomized cross-over study. Fourteen had pituitary hormone deficiency (PHD) including GH deficiency (GHD). Of the 14 patients, seven were ACTH sufficient (PHDC+) and seven ACTH deficient (PHDC-). Six had primary adrenal failure (PAF). Subjects administered or omitted their normal dose of evening GH and/or morning hydrocortisone. Glucose, insulin, GH, cortisol, ketones and catecholamines were measured at 04.00 h and regularly from 07.00 to 12.00 h. Insulin sensitivity was assessed by HOMA and hypoglycaemia defined as a blood glucose (BG) </= 3.3 mmol/l.

RESULTS

BG was related to age and body mass index on treatment but no subject became hypoglycaemic on or off therapy prior to 07.00 h. Five children (aged 3, 4, 7, 8 and 11 years) were hypoglycaemic between 07.00 and 12.00 h off treatment. There was a positive relationship between GH AUC and minimum BG in patients with PHD on treatment (r(2) = 0.45, P = 0.012) with increased insulin sensitivity off treatment. Increased cortisol levels were seen in PHDC+ patients off GH (P < 0.001). A negative relationship was observed between minimum BG and adrenaline (r(2) = 0.37, P = 0.01), ketone bodies (r(2) = -0.20, P = 0.05) and NEFA (r(2) = -0.35, P = 0.02). Noradrenaline levels were reduced in patients with PHDC-. Low BMI (on treatment) and young age (off treatment) were determinants of low BG levels in a multiple regression model.

CONCLUSIONS

Unrecognized overnight hypoglycaemia in children and adolescents on pituitary hormone replacement is uncommon but BG levels quickly become abnormal when treatment and meals are omitted. The insulin antagonistic actions of GH are important in preventing hypoglycaemia. Patients with PHD have altered sympathetic nerve activity.