Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women

OBJECTIVE: To compare the effects of isocaloric, energy-restricted very low-carbohydrate ketogenic (VLCK) and low-fat (LF) diets on weight loss, body composition, trunk fat mass, and resting energy expenditure (REE) in overweight/obese men and women. DESIGN: Randomized, balanced, two diet period clinical intervention study. Subjects were prescribed two energy-restricted (-500 kcal/day) diets: a VLCK diet with a goal to decrease carbohydrate levels below 10% of energy and induce ketosis and a LF diet with a goal similar to national recommendations (%carbohydrate:fat:protein = ~60:25:15%). SUBJECTS: 15 healthy, overweight/obese men (mean +/- s.e.m.: age 33.2 +/- 2.9 y, body mass 109.1 +/- 4.6 kg, body mass index 34.1 +/- 1.1 kg/m2) and 13 premenopausal women (age 34.0 +/- 2.4 y, body mass 76.3 +/- 3.6 kg, body mass index 29.6 +/- 1.1 kg/m2). MEASUREMENTS: Weight loss, body composition, trunk fat (by dual-energy X-ray absorptiometry), and resting energy expenditure (REE) were determined at baseline and after each diet intervention. Data were analyzed for between group differences considering the first diet phase only and within group differences considering the response to both diets within each person. RESULTS: Actual nutrient intakes from food records during the VLCK (%carbohydrate:fat:protein = ~9:63:28%) and the LF (~58:22:20%) were significantly different. Dietary energy was restricted, but was slightly higher during the VLCK (1855 kcal/day) compared to the LF (1562 kcal/day) diet for men. Both between and within group comparisons revealed a distinct advantage of a VLCK over a LF diet for weight loss, total fat loss, and trunk fat loss for men (despite significantly greater energy intake). The majority of women also responded more favorably to the VLCK diet, especially in terms of trunk fat loss. The greater reduction in trunk fat was not merely due to the greater total fat loss, because the ratio of trunk fat/total fat was also significantly reduced during the VLCK diet in men and women. Absolute REE (kcal/day) was decreased with both diets as expected, but REE expressed relative to body mass (kcal/kg), was better maintained on the VLCK diet for men only. Individual responses clearly show the majority of men and women experience greater weight and fat loss on a VLCK than a LF diet. CONCLUSION: This study shows a clear benefit of a VLCK over LF diet for short-term body weight and fat loss, especially in men. A preferential loss of fat in the trunk region with a VLCK diet is novel and potentially clinically significant but requires further validation. These data provide additional support for the concept of metabolic advantage with diets representing extremes in macronutrient distribution.     

Awareness of risk factors for cancer among British adults

Awareness of risk factors for five common cancers was assessed in a representative sample of 3 693 adults in the UK. Respondents were presented with a risk of 14 factors comprising 10 which have established links with various cancers (older age, many sexual partners, low fibre diet, smoking, a relative with the cancer, low fruit and vegetable diet, taking HRT/the contraceptive pill, being overweight, viruses or infection, and a high fat diet) and four so-called "mythic" causes (food additives, overhead power lines, pollution, stress). Out of 15 well-established associations between risk factors and cancers, the average number correctly identified was 5. Women and those with higher levels of education got more correct. Endorsement of mythic causes was comparatively low (less than 5% for most cancers), but were higher in men and those with less education. These results are somewhat reassuring in relation to the prevalence of erroneous beliefs, but raise considerable concern about public understanding of well established causes. Better health education will be needed to maximise public awareness of cancer prevention.     

Aetiology and classification of small for gestational age infants

Objective: To determine important aetiological factors in small gestational age (SGA) infants and the effectiveness of anthropometric indexes in identifying patterns of growth retardation.
Methodology: Eighty-four SGA infants and 81 controls were enrolled. Maternal biological, lifestyle and psychosocial factors were compared for the total group and the term Caucasian subset. Anthropometric indexes were also examined in relation to growth patterns.
Results: Decreased maternal size, poor weight gain, previous SGA infant and smoking were significantly associated with SGA status. Poor parental education and unemployment was increased in the study group. Mothers of SGA infants, especially the term Caucasian group, had a greater prevalence of hypertension and depressive and stress symptomatology. Ponderal index failed to identify discreet patterns of disproportionate/proportionate growth retardation.
Conclusion: Biological, lifestyle and psychosocial differences remain important aetiological factors of intrauterine growth retardation. Identification of specific patterns of growth retardation by ponderal index remains controversial.     

Comparison of milk and maize based diets in kwashiorkor

The dual sugar test of intestinal permeability is a reliable non-invasive way of assessing the response of the small intestinal mucosa to nutritional rehabilitation. AIM: To compare a local mix of maize-soya-egg to the standard milk diet in the treatment of kwashiorkor. DESIGN: The diets were alternated three monthly in the sequence milk-maize-milk. There were a total of 533 kwashiorkor admissions of at least five days during the study who received either milk or maize. Intestinal permeability was assessed at weekly intervals by the lactulose-rhamnose test in 100 kwashiorkor cases, including 55 on milk and 45 on the maize diet. RESULTS: Permeability ratios (95% confidence interval) on the milk diet improved by a mean of 6.4 (1.7 to 11.1) compared with -6.8 (-16.8 to 5.0) in the maize group. The improved permeability on milk occurred despite more diarrhoea, which constituted 34.8% of hospital days (29.8 to 39.8) compared with 24.3% (17.8 to 30.8) in the maize group. Case fatality rates for all 533 kwashiorkor admissions were 13.6% v 20.9%, respectively, giving a relative risk of death in the maize group of 1.54 (1.04 to 2.28). The maize group also had more clinical sepsis (60% v 31%) and less weight gain (2.9 v 4.4 g/kg/day) than the milk group. IMPLICATIONS: Milk is superior to a local maize based diet in the treatment of kwashiorkor in terms of mortality, weight gain, clinical sepsis, and improvement in intestinal permeability.     

Nitric oxide activity in childhood hypertension

OBJECTIVES: To investigate nitric oxide (NO) activity in childhood hypertension using nitrite and nitrate (NOx) concentrations in plasma as an index of nitric oxide generation. DESIGN: Cross sectional study. SETTING: Tertiary care paediatric centre and district general hospitals in the UK. PATIENTS: Children attending the above centre for treatment of hypertension. The control subjects were normotensive healthy children attending district general hospitals for minor medical and surgical disorders. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Plasma (P) and urinary (U) NOx concentrations, blood pressure, and glomerular filtration rate. RESULTS: Sixteen normal children (mean age 6.9 years), 13 children with renovascular hypertension (mean age 7.8 years), and 25 children with hypertension associated with renal parenchymal disease (mean age 10.7 years) were studied. Mean (SD) PNOx values of children with hypertension with renovascular disease (15.3 (11.4) mumol/l) and renal parenchymal disease (18.3 (11.4) mumol/l) were significantly above that of normal children (11.9 (5.9) mumol/l) after accounting for age and glomerular filtration rate influences. Higher concentrations of PNOx in normal children were associated with younger age, but not in the children with hypertension. Higher PNOx concentrations were also associated with a lower glomerular filtration rate in normal children and children with hypertension with renal parenchymal disease, but not in the children with hypertension with renovascular disease. UNOx excretion expressed as a ratio against urine creatinine (Ucreat) excretion was not statistically different among the study groups. CONCLUSIONS: PNOx is increased in children with hypertension even after statistical elimination of the glomerular filtration rate and age influences. This suggests a normal or increased NO synthase activity in childhood hypertension in contrast with adults with hypertension in whom it is described as reduced.     

Varicella and zoster in children after kidney transplantation: long-term results of vaccination

OBJECTIVE: To determine the long-term prevalence of varicella infection and herpes zoster after kidney transplantation and to assess the effectiveness of varicella immunization with the Oka attenuated strain. METHODS: This study involved 704 children and adolescents who received a kidney graft in our institution from 1973 to 1994 and had routinely been given varicella vaccine beginning in 1980 in preparation for transplantation. RESULTS: After vaccination 62% of these patients still had varicella/zoster (VZ) antibodies at 1 year and 42% after 10 years. After transplantation the incidence of varicella was significantly lower, 26/212 (12%), in patients who received immunization than in those who did not and had no history of varicella, 22/49 (45%). The disease was also significantly less severe in the vaccinated patients (three deaths among naive patients vs none among vacciness). In the vaccinees, varicella infection was observed only in those who did not develop or lost VZ antibodies; in addition, 21 patients of this subgroup had an asymptomatic seroconversion. Four of the 415 patients with a history of varicella had another episode of benign varicella after grafting. Herpes zoster was observed in 76 of the 704 patients included in the study. The prevalence differed according to VZ status at the time of grafting: 13% in patients with a history of varicella, 7% in the vacciness, and 38% in the naive patients at grafting who developed varicella. Three rejection episodes occurred in association with a varicella episode and four with a zoster episode, but graft function was only transiently impaired, and as a whole varicella or zoster did not significantly affect graft function or survival. CONCLUSION: Naive VZ patients with a kidney graft are at risk to develop severe varicella and this may be effectively prevented by available immunization.     

Altered gap junctional intercellular communication in neoplastic rat esophageal epithelial cells

Gap junctional intercellular communication (GJIC) is reduced in many neoplastic cells, but few data exist for esophageal neoplasms. GJIC was examined by fluorescent dye microinjection in two nontumorigenic and two highly tumorigenic rat esophageal epithelial cell lines. All lines expressed high levels of dye coupling in homologous cell culture. In cocultures of nontumorigenic and tumorigenic cells, however, only one of six cell combinations displayed significant heterologous GJIC. Northern, Western, and immunohistochemical analyses indicated that all four cell lines expressed comparable levels of connexin43 (Cx43), but not connexin32 or connexin26, and formed Cx43-containing gap junction plaques at cell-cell interfaces. Immunostaining of rat esophageal frozen sections demonstrated that esophageal epithelial cells expressed Cx43 in vivo. In normal epithelium, the highest expression was seen in the basal cells and little suprabasal staining was evident. In preneoplastic and neoplastic lesions of the esophageal epithelium which were induced by treating rats with N-nitrosomethylbenzylamine, Cx43 staining of the basal layer was also seen but appeared to be more diffuse compared to normal epithelium. In addition, suprabasal Cx43 staining was apparent in dysplastic and papillomatous lesions. These results indicate that Cx43 is expressed in normal and neoplastic rat esophageal cells and that the cells exhibit extensive homologous GJIC, but little heterologous GJIC. This lack of heterologous GJIC may be due to differences in cell adhesion proteins or other factors.      

Skin dose from radiotherapy X-ray beams: The influence of energy

Skin-sparing properties of megavoltage photon beams are compromised by electron contamination. Higher energy beams do not necessarily produce lower surface and basal cell layer doses due to this electron contamination. For a 5 ± 5cm field size the surface doses for 6 MVp and 18MVp X-ray beams are 10% and 7% of their respective maxima. However, at a field size of 40x40cm the percentage surface dose is 42% for both 6 MVp and 18 MVp beams. The introduction of beam modifying devices such as block trays can further reduce the skin-sparing advantages of high energy photon beams. Using a 10mm perspex block tray, the surface doses for 6MVp and 18MVp beams with a 5x5cm field size are 10% and 8%, respectively. At 40x40cm, surface doses are 61 % and 63% for 6MVp and 18MVp beams, respectively. This trend is followed at the basal cell layer depth. At a depth of 1 mm, 18 MVp beam doses are always at least 5% smaller than 6 MVp doses for the same depth at all field sizes when normalized to their respective Dmax values. Results have shown that higher energy photon beams produce a negligible reduction of the delivered dose to the basal cell layer (0.1 mm). Only a small increase in skin sparing is seen at the dermal layer (1 mm), which can be negated by the increased exit dose from an opposing field.