Body Water, Lean Body and Fat Mass of Healthy Children as Measured by Deuterium Oxide Dilution

Association between foot growth and musculoskeletal loading in children with Prader-Willi syndrome before and during growth hormone treatment

OBJECTIVE

To explore how foot growth relates to musculoskeletal loading in children with Prader-Willi syndrome (PWS).

STUDY DESIGN

In 37 children with PWS, foot length (FL) before and after 6 years of growth hormone therapy (GHT) was retrospectively evaluated with parental and sibling's FL, height, and factors reflecting musculoskeletal loading, such as weight for height (WfH), lean body mass (LBM; dual energy X-ray absorptiometry, deuterium labeled water), physical activity (accellerometry), and walk age. Because of the typically biphasic evolution of body mass and the late walk age in PWS, 2 age groups were separated (group 1, >2.5 years; group 2, < or =2.5 years).

RESULTS

Children with PWS normalized height, but not FL after 6 years of GHT. Parental FL correlation with PWS's FL was lower than with sibling's FL. In group 1, FL positively correlated with WfH, LBM, and physical activity. In group 2, FL negatively correlated with age at onset of independent ambulation. Foot catch-up growth with GHT was slower in group 2 compared with group 1.

CONCLUSION

In PWS, FL is positively associated with musculoskeletal loading. Small feet in children with PWS before and during long-term GHT may be more than just another dysmorphic feature, but may possibly reflect decreased musculoskeletal loading influencing foot growth and genetic and endocrine factors.

Developmental profiles in young children with Prader-Labhart-Willi syndrome: effects of weight and therapy with growth hormone or coenzyme Q10

Muscle hypotonia and failure to thrive are key symptoms of Prader-Willi syndrome (PWS) allowing diagnosis during infancy already. Improved general care as well as Coenzyme Q(10) (CoQ(10)) and growth hormone (GH) are administered to improve PWS children's outcome. This study aims to investigate psychomotor development of young PWS children in relation to body weight and body composition at baseline as well as to the effects of GH or CoQ(10) therapy. Twenty-six young children (age 1.0 +/- 0.1 years, mean +/- SEM) with PWS genetically proven at age 0.1 +/- 0.1 years (17 deletions, 8 maternal disomy) were divided into three groups: Group 1 on GH therapy (started in 1994-1996, 6 mg/kg/week) tolerating low body weight (<50th centile), group 2 on GH (1997-2000) and group 3 on CoQ(10) (2001-2002, 2.5 mg/kg/day orally), both combined with active early weight management to achieve weight >50th centile. Anthropometry, body composition and Griffith's developmental scores (DQs) were assessed before therapy and after 12 months. DQs were not related to infants' weight, lean mass or genetic background. DQs improved significantly with chronological age and were best in the most recently diagnosed group. Improved psychomotor development, mainly due to progress in locomotor development, did not differ between GH and CoQ(10) treated groups. In conclusion, while only GH has significant effects on growth and body composition, GH and CoQ(10) therapy act equally on psychomotor development of PWS infants. However, improving psychomotor development may merely reflect an age-related phenomenon additionally depending on early diagnosis and introduction of appropriate care.

Clinical evaluation of time-resolved spectroscopy by measuring cerebral hemodynamics during cardiopulmonary bypass surgery

We developed a three-wavelength time-resolved spectroscopy (TRS) system, which allows quantitative measurement of hemodynamics within relatively large living tissue. We clinically evaluated this TRS system by monitoring cerebral circulation during cardiopulmonary bypass surgery. Oxyhemoglobin, deoxyhemoglobin, total hemoglobin and oxygen saturation (SO(2)) were determined by TRS on the left forehead attached with an optode spacing of 4 cm. We also simultaneously monitored jugular venous oxygen saturation (SjvO(2)) and arterial blood hematocrit (Hct) using conventional methods. The validity and usefulness of the TRS system were assessed by comparing parameters obtained with the TRS and conventional methods. Although the changes in SO(2) were lower than those in SjvO(2), SO(2) obtained by TRS paralleled the fluctuations in SjvO(2), and a good correlation between these values was observed. The only exceptions occurred during the perfusion period. Moreover, there was a good correlation between tHb and Hct values (r(2)=0.63). We concluded that time-resolved spectroscopy reflected the conditions of cerebral hemodynamics of patients during surgical operations.

Growth hormone and body composition in children younger than 2 years with Prader-Willi syndrome

OBJECTIVES

To assess body composition of infants with Prader-Willi syndrome (PWS) by using deuterium dilution and investigating the efficacy of early institution of growth hormone (GH) therapy in increasing lean mass (LM) and preventing massive obesity.

STUDY DESIGN

One group of 11 children with PWS <2 years before and during 30-month GH therapy (GH group) was compared with 6 infants administered only coenzyme Q(10) for 1 year (Q10 group). LM adjusted for height (LM(Ht)) and relative fat mass (%FM(Age)) standard deviation scores (SDS) were calculated from data of 95 healthy children.

RESULTS

Initially, LM(Ht) of all patients was below the normal average. LM(Ht) decreased by -0.46 +/- 0.3 SD (P=.03) per year in the Q10 group but rose by 0.25 +/- 0.3 SD (P=.02) per year during GH therapy, normalizing after 30 months (-0.70 +/- 1.0 SD). Despite low to normal weight for height (WfH), %FM(Age) was above the normal average (GH group, 31.0% +/- 4.5%, Q10 group, 32.4% +/- 9.5%). In the Q10 infants, %FM(Age) increased by 0.71 +/- 0.7 SD per year, whereas in the GH group, %FM(Age) remained more stable up to 30 months.

CONCLUSIONS

Diminished LM(Ht) found in infants with PWS further declines during the early years. Early institution of GH therapy lifts LM(Ht) into the normal range and delays fat tissue accumulation.