Table 3.
Results of cognitive function, behaviour, motor development and quality of life
| Author | Test type | Results |
| Cognitive function | ||
| Dykens EM et al 13 | Cognition: KBIT-2 (verbal IQ, non-verbal IQ, composite IQ) VABS-II (communication and daily live skills, socialisation, adaptive composite). | Children receiving GHT had significantly higher verbal and composite IQs, and adaptive communication and daily living skills. Those who started before 12 months of age had higher non-verbal and composite IQs. |
| Donze SH et al 15 | Psychomotor development (Bayley Scales of Infants II -BSID-II - mental and motor development) | During 3 years of GH, mental development increased from 58.1% (2.8) at baseline to 79.6% (3.7) (p<0.01). A lower baseline psychomotor development and a younger age at start of GH treatment were associated with a higher increase in mental development (p<0.01). No control group for this analysis. |
| Lo ST 201536 | VABS-II, cognitive function: BSID-II, Wechsler Preschool and Primary Scale of Intelligence-Revised Dutch version | Starting GH treatment at an earlier age during infancy led to better adaptive skills on the long-term. No effect in short-term. BSD-II already described in Festen 2008. |
| Siemensma EPC et al 14 | WISC-R (Vocabulary, similarities, block design and picture arrangement) and Wechsler Preschool and Primary Scale of Intelligence-Revised Dutch version | In short-term, rhGH prevented deterioration of certain cognitive skills (similarities and vocabulary domain) and significantly improved abstract reasoning and visuospatial skills during 4 years of GH treatment. Children with lower cognitive functioning at baseline, GH treatment had a greater effect on abstract verbal reasoning and visuospatial skills in comparison with control group. |
| Festen DAM et al 16 | Mental development Bayley Scales of Infant Development II (BSID-II) | Mental development improved significantly during the first year of study in the GH group versus the control group: median (IQR) change was +9.3% (-5.3 to 13.3) versus -2.9% (8.1 to 4.9) (p<0.05) in mental development. |
| Myers SE44 | Language/ cognition (age of first spoken word and Capute scales of Infants language) | GH-treated PWS group progressed significantly more during the first year in both language and cognitive development than the PWS control group; First words were spoken at 14 months, in 12 subjects treated before their first birthday and 17.2 in late-treated subjects, compared with reported data for global PWS of 21–23 months. |
| Böhm B et al 33 | Cognition (Raven's Standard, Progressive Matrices test, Arthur's adaptation of Leiter's Performance Scale; SPIQ test, Terman's Scale of intelligence, Bender Gestalt test, Harris Draw-a-Man) | No difference was found in these patients (mean age 6.3 years) regarding cognitive function. |
| Behaviour outcome | ||
| Dykens EM et al 13 | Repetitive Behaviour Scale and Adaptive Behaviour | rhGH treated versus treatment naïve 4 to 21 years old children with PWS had significantly higher adaptive behaviour standard scores, but no differences in repetitive behaviour scales. |
| Lo ST et al 34 | Behaviour (Developmental Behaviour Checklist of Children with intellectual disability and Children Social Behaviour Questionnaire) | No difference reported. |
| Whitman BY et al 17 | Behaviour (Offord Survey Diagnostic Instrument and Family Inventory of Life Events) | No differences between groups; however, a significant positive effect (reduction of depressive symptoms) was noted for the treated group |
| Böhm B et al 33 | Behaviour (specific test for this study) | No difference between groups. Successively worsened behaviour after discontinuing GH treatment. |
| Motor development/ muscle strength | ||
| Donze SH et al 15 | Psychomotor development (BSID-II - mental and motor development) | During 3 years of GH, mean motor development increased from 41.9% (2.9) to 78.2% (3.9) (p<0.01). A lower baseline psychomotor development and a younger age at start of GH treatment were associated with a higher increase in motor development (p<0.01). |
| Reus L et al 37 | Muscular thickness by ultrasound | GH has a positive effect on muscle thickness (biceps; forearm flexor, quadriceps and tibialis anterior) in PWS infants. |
| Reus L et al 35 | Muscle strength (Infant Muscle Strength Meter - AIMS) and Motor function (Gross Motor Function Measure - GMFM); Bayley Scales of Infants II- BSD-II | The AIMS and GMFM clearly revealed a significant a positive effect of GH on motor development; the child’s maximum motor potential increased with GH treatment, thereby resulting in a clear functional improvement. BSID-II revealed no effect of GH on motor development. |
| Festen DAM et al 16 | Motor and mental development. Bayley Scales of Infant Development II (BSID-II) | Significant improvement in motor development (+11.2% vs −18.5%) at the first year of treatment in the treated group versus control group from the baseline. |
| Myers SE et al 44 | Motor development (age of walking and Toddler and Infant Motor Evaluation) | A trend towards improved mobility and stability percentile rankings was noted with GH therapy, however, wide variability among PWS subjects was seen at all time points. Eleven PWS subjects treated before their first birthday walked independently at a mean age of 23.5 months. Five late-treated PWS subjects walked independently at a mean age of 24.3 months. |
| Carrel AL et al 40 | Muscular strength | Documented changes in physical function (strength and agility testing) in PWS children treated with GH in first 2 years therapy, but no change in the following 2 years. |
| Carrel AL et al 5 | Muscular strength and agility (agility run, broad jump, sit-ups in 20 s and upper extremity strength) | Agility run (faster by 2.3±0.5 s), broad jump (farther by 3.3±1.9 inches), abdominal strength (an improvement of 3.0±2.1 sit-ups/20 s) and upper extremity strength (increase of 2.5±1.8 weight-lift repetitions/30 s); compared with baseline performance |
| Quality of life | ||
| Bakker NE et al 18 | DUX25 and DUXPW questionnaires for children and parents | GH-treated children showed a significant improvement in health -related quality of life during the 2-year RCT in the physical subdomain of the DUX25 and the DUXPW, compared with the untreated ones. During long-term GH treatment (11 year), questionnaires scores remained stable. Social subdomain was higher in children with a deletion than in children with an uniparental disomy or imprinting defect, according to parents |
| Sipilä I et al 39 | 16D (generic 16-dimension health-related quality of life) instrument for adolescents | The effect of rhGH therapy remains unclear because of a lack of untreated control group with PWS and lack of comparable baseline measurements for evaluating changes over time. |
GH, growth hormone; GHT, GH therapy; IQs, intelligent quotients; PWS, Prader-Willi syndrome; RCT, randomised controlled trial; rhGH, recombinant human GH.