L. C. K. Low

The timing of early postnatal catch-up growth in normal, full-term infants born short for gestational age

Postnatal catch-up growth in infants born small for gestational age has been reported to occur mainly during the initial 3-9 months of life. The study presented here characterized early postnatal growth in healthy, full-term infants born short for gestational age (GA) (< -2 standard deviation scores [SDS] in birth length) in two populations. Results from a longitudinal growth study from birth to final height of 139 infants born short for GA between 1973 and 1975 in Göteborg, Sweden, were compared with results from an ongoing detailed prospective 6-month follow-up of 41 Hong Kong Chinese infants born short for GA in 1995 and 1996. For both populations, height was expressed in SDS using the updated Swedish growth reference data at birth and postnatally. In the Swedish study, 92% of the children born short for GA reached a final height greater than -2 SDS; 76% had a height greater than -2 SDS by 2 months of age. In the Hong Kong study, 79% reached a height greater than -2 SDS by 5 months of age (the longest follow-up time to date). A third population of Hong Kong Chinese infants born short for GA in 1967 was studied; 65% had reached the normal height range by 5 months of age. In the later Hong Kong study (1995-1996), catch-up growth could be identified as early as 12 weeks of age, which has important implications for clinical practice. Thus, growth monitoring during the first weeks of postnatal life gives useful information on catch-up growth in infants born short for GA.

Goitrogenesis during pregnancy and neonatal hypothyroxinaemia in a borderline iodine sufficient area

Severe iodine deficiency disorders (IDDs) may have been eradicated in many parts of the world, but milder forms still exist and may escape detection. We evaluated the impact of pregnancy on the maternal and fetal thyroid axis in Hong Kong, a coastal city in southern China with borderline iodine intake.

A cross-sectional study of growth, puberty and endocrine function in patients with thalassaemia major in Hong Kong

Methodology: A cross‐sectional study of growth, puberty and endocrine function was performed on 35 girls and 33 boys with thalassaemia major.

Strong Association of HLA-DR3/DRw9 Heterozygosity With Early-Onset Insulin-Dependent Diabetes Mellitus in Chinese

Studies of Caucasian and Japanese patients with insulin-dependent diabetes mellitus (IDDM) have shown that heterozygosity for certain HLA-DR antigens confers a high risk of developing the disease. The HLA antigens of 75 Chinese patients and 100 Chinese controls in Hong Kong were studied to investigate the role of HLA-DR heterozygosity in Chinese individuals. Some of the patients and controls were also tested for allotypic variation in the complement components C2, C4, and BF. Three alleles, Aw33, B17, and DR3, had increased frequencies in patients compared with controls and frequently occurred together in the same phenotype, which suggested their existence as a haplotype. There were no statistically significant differences in complement allotype frequencies between patients and controls, although the C4B null allele seemed to be associated with Aw33, B17, and DR3. No other HLA-DR antigen appeared to be associated with IDDM. However, when the patients were separated on the basis of age at onset, the frequency of DR3/DRw9 heterozygosity was markedly increased in patients presenting in the first decade of life, but there was no increase in patients presenting at greater than 20 yr of age. DRw9 is strongly associated with autoimmune disease in Chinese, whereas DR3 is not. We suggest that the major IDDM susceptibility locus in Chinese is associated with HLA-DR3 and that patients with HLA-DR3 and HLA-DRw9 have an added predisposition to autoimmune disease and therefore develop IDDM earlier than patients without DRw9.

Invasive Haemophilus influenzae type b infections in children hospitalized in Hong Kong, 1986–1990

A 5‐year territory‐wide retrospective survey of invasive Haemophilus influenzae type b diseases was conducted in Hong Kong. Between 1986 and 1990, 57 cases (28 male) were recorded in children less than 12 years old (37 cases of meningitis, 9 of septicaemia and 11 of bacteraemic pneumonia). The annual incidence for children less than 5 years old was 2.7 per 105 (95% confidence interval (CI) 2.0–3.5). Of the 57 cases, 39 were Chinese and 18 non‐Chinese (7 Vietnamese refugees, 6 Caucasians, 5 others). The annual incidence in Vietnamese refugees less than 5 years old was 42.7 per 105 (95% CI 17.2–87.9), giving a relative risk of 18.5 (95% CI 8.3–41.0). Chinese patients (68%) were under‐represented as Chinese accounted for at least 94% of the population. Moreover, 14 of the 39 Chinese patients had pre‐existing medical problems, compared with only 1 of the 18 non‐Chinese patients (p= 0.022).

Iodine insufficiency and neonatal hyperthyrotropinaemia in Hong Kong.

OBJECTIVESu200323% of the neonatal hypothyroidism in Hong Kong is transient. The present study aims to evaluate iodine excretion in healthy pregnant women in Hong Kong and to determine whether iodine insufficiency may occur in the local population to account for the type of neonatal thyroid dysfunction seen in our screening programme.

Serum growth hormone (GH) binding protein, IGF-I and IGFBP-3 in patients with β-thalassaemia major and the effect of GH treatment

Levels of IGFI have been shown to be low in transfusion‐dependent thalassaemia and there is preliminary evidence to suggest that this may be reversed by GH treatment. In this further study we have evaluated serum growth hormone (GH) binding protein (GHBP), IGF‐I and IGFBP‐3 in patients with β‐thalassaemia major and the effects of GH treatment on these various parameters.

Growth hormone treatment of short Chinese children with β‐thalassaemia major without GH deficiency

OBJECTIVE Despite regular transfusion and desferoxamine treatment, growth failure Is commonly seen In adolescent children with β‐thalassaemla major. The growth failure has been thought to be due to GH resistance rather than GH deficiency. We Investigated the effect of GH on short non‐GH deficient children with β‐thalassaemia.

Defective neutrophil and lymphocyte function in leucocyte adhesion deficiency

We report a Chinese girl with the moderate phenotype of leucocyte adhesion deficiency (LAD), presenting with persistent omphalitis and recurrent soft tissue infections. She had subnormal adhesion‐dependent neutrophil functions, such as chemotaxis and chemiluminescence response to a particulate stimulant (opsonised zymosan). Despite her adequate humoral response to documented herpes simplex virus type 1, parainfluenza type 2 and adenovirus infection in vivo. there was marked impairment in the generation of plaque‐forming cells (PFC) driven by pokeweed mitogen (PWM) in vitro. IgM PFC were less severely affected than IgG and IgA PFC, probably because IgM production is less dependent on T cell help than IgA and IgG production. The patients B cells and accessory cells had reduced function compared with the control subsets, while helper function of her CD4+ cells was virtually absent in the PWM‐driven PFC assay. She also had marked defect in natural killer cell activity. The proliferation of her lymphocytes was normal to several plant Iectins, including phytohaemagglutinin, concanavalin A and PWM, but markedly defective to OKT3.

A comparison of target height estimated and final height attained between Swedish and Hong Kong Chinese children.

Target height, the genetic potential in stature, is commonly estimated by the corrected midparental height (CMH) method. A new model for estimating target height has recently been introduced based on a large, Swedish, population‐based study. The aim of this study was to compare the validity of the two methods for estimating target height in Hong Kong Chinese children. The Hong Kong Chinese were more than 10 cm shorter than the Swedes in stature. The secular increase in height over the two generations, however, was 4.2‐4.8 cm for the Hong Kong Chinese, much larger than that of the Swedes (0.7‐1.0 cm). The two populations are thus at different stages in the secular trend. The new model derived from Swedish population for estimating target height was shown to be applicable to Hong Kong Chinese children; the mean of residual final height values was close to zero (–0.15 cm, p = 0.74). However, the mean of residual final height was significantly above the expected value of zero (4.5 cm, p < 0.0001) when the CMH method was applied to the data, which implies an underestimation bias of 4.5 cm. Consequently, if the CMH method is used to estimate target height and evaluate growth hormone treatment responses in short children, it may inflate the treatment response by 4.5 cm. In conclusion, the recently proposed model for target height estimation offers a better alternative for estimating target height in Hong Kong Chinese children and for assessing growth‐promoting treatments.