Dietary Intake and Metabolic Control of Children with Type 1 Diabetes Mellitus Aged 6-10 Years in KwaZulu-Natal

Objectives: The objective of this study was to assess the dietary intake and metabolic control of children with type 1 diabetes. Design: A cross-sectional observational study was carried out. Subjects: A total of 30 subjects whose ages ranged from six to ten years were included in the study. Setting: The study was conducted at the Paediatric Diabetic Clinics at Grey's Hospital; Pietermaritzburg and Inkosi Albert Luthuli Central Hospital (IALCH); Durban; in KwaZulu-Natal. Outcome measures: Dietary intake was assessed using a three-day dietary record. Metabolic control was assessed using glycosylated haemoglobin (HbA1c). Results: The mean percentage contributions of macronutrients to total energy as determined by the three-day dietary records were as follows: carbohydrate - 52; added sucrose - 2; protein - 16; fat - 32. The mean intakes were similar to the recommendations of the International Society for Pediatric and Adolescent Diabetes (ISPAD) Consensus Guidelines (2002). Micronutrient intake was generally adequate. The mean latest glycosylated haemoglobin (HbA1c) for the sample as at the time of the study was 9.7. Five of the thirty subjects had HbA1c values that were within the recommended levels for children with type 1 diabetes. Conclusions: The macronutrient intake in this sample was found to be similar to the ISPAD Consensus Guidelines (2002) while micronutrient intake was adequate in most cases. Overall the sample had poor metabolic control

Are South African Women Willing and Able to Apply the New Food-Based Dietary Guidelines? Lessons for Nutrition Educators

"Background :Consumer testing was a prime consideration in developing specific South African food-based dietary guidelines (FBDGs) which were nationally adopted in 2003.Objectives This study aimed to determine the consumer's ability to apply the FBDGs appropriately; in terms of identifying foods/drinks according to the FBDG food categories; perceived importance of and barriers to applying each FBDG; and planning a typical day's meals to reflect the FBDGs. Design A cross-sectional study of 333 women from different cultural and socio-economic backgrounds. Setting KwaZulu-Natal; South Africa. Methods Data collection comprised focus-group discussions (n = 103) and structured individual interviews (n = 230). Results The identification of foods/drinks according to the FBDG food categories reflected a high level of comprehension by participants of these food categories. Participants from all study samples endorsed the importance of applying the FBDGs; predominantly for health reasons. Participants cited barriers to the application of the FBDGs as affordability; availability; household taste preferences; routine food-purchasing habits; time constraints; traditional/ habitual food-preparation methods; and persistent attitudes. Only three FBDGs were mentioned as difficult to apply; namely; ""fruits/ vegetables""; ""foods from animals"" and ""legumes"". Meal plans did reflect the FBDGs; illustrating the flexibility of their use across cultural and socio-economic differences. Conclusions Consumer testing of the FBDGs was mainly positive. The study has highlighted areas of confusion regarding certain concepts; terminology and misconceptions; and has identified barriers to application. These concerns can be addressed through the reformulation and retesting of certain dietary guidelines; and the provision of explanatory consumer information and health-worker training materials."

Effect of 1,25-dihydroxyvitamin D3 on plasma concentrations of calcium-binding protein in normal and rachitic (vitamin D-dependent rickets type I) pigs.

An i.v. injection of calcitriol (1,25-(OH)2D3) had no effect within 2.5 h on plasma concentrations of calbindin-D9K (vitamin D-induced calcium-binding protein; CaBP) in hypocalcaemic pigs with inherited vitamin D-dependent rickets type I or in their normocalcaemic siblings or half-siblings. Three days later the plasma concentration of CaBP had doubled in the hypocalcaemic pigs, but was unaltered in the normocalcaemic siblings and half-siblings. Following daily i.v. injections of 1,25-(OH)2D3 for a further 5 days (days 4-8) plasma concentrations of CaBP increased in both the hypocalcaemic (days 4-8) and normocalcaemic (day 8) pigs, the effect being more rapid and greater in the hypocalcaemic 1,25-(OH)2D3-deficient animals. An i.v. injection of 1,25-(OH)2D3 to pure Yucatan pigs also had no effect on plasma concentrations of CaBP within 1.5 h, but in the following 1 h there was some indication of an increase in plasma CaBP levels. In contrast to the normal pigs, insulin-induced hypoglycaemia did not lead to a peak in plasma CaBP concentrations in the hypocalcaemic pigs. There was also no change in the plasma concentrations of 1,25-(OH)2D3 associated with the peak in plasma CaBP following insulin-induced hypoglycaemia in normocalcaemic pigs. These results suggest that changes in plasma concentrations of 1,25-(OH)2D3 are not directly involved in mediating the increase in plasma CaBP which follows hypoglycaemia induced by insulin in normal pigs, although 1,25-(OH)2D3 probably plays a permissive role.

Endocrine control of plasma concentrations of calcium-binding protein in the pig.

The aetiology of the rise in plasma calbindin-D9K (vitamin D-induced calcium-binding protein; CaBP), following insulin-induced hypoglycaemia, was studied in the pig. ACTH led to a rise in plasma concentrations of both CaBP and cortisol. Metyrapone, which blocks cortisol synthesis, abolished the increases in plasma concentrations of CaBP and cortisol normally observed in response to insulin-induced hypoglycaemia. However, there was no significant rise in plasma concentrations of CaBP in response to pharmacological or physiological doses of cortisol. Injection of clonidine, an alpha 2-adrenergic agonist, led to a rise in plasma concentrations of CaBP, whereas phenylephrine, an alpha 1-adrenergic agonist, tended to exert an inhibitory effect. Also, administration of phentolamine (an alpha-adrenergic blocker) before injection of insulin abolished the usual increase in plasma concentrations of CaBP, whereas propranolol (a beta-adrenergic blocker) enhanced the normal increase in plasma concentrations of CaBP in response to insulin-induced hypoglycaemia. Isoproterenol, a beta-adrenergic agonist, was without effect on plasma CaBP. Neither GH nor glucagon appear to be involved in the rise in plasma CaBP following insulin-induced hypoglycaemia. Although atropine abolished the effect of acute hypoglycaemia on plasma CaBP, carbamylcholine was without effect on plasma CaBP concentration. It is concluded that the increases in plasma CaBP induced by either ACTH or alpha 2-adrenergic stimulation may be interrelated since the administration of ACTH can lead to raised plasma concentrations of catecholamines.

Hypophosphataemia and vitamin D metabolism in sheep.

The effect of dietary induced hypophosphataemia on vitamin D metabolism was studied in four conscious sheep. No change in the plasma concentrations of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) were found during hypophosphataemia when compared with normophosphataemia. In addition both the metabolic clearance rate and the production rate of plasma 1,25(OH)2D3 were unaltered during hypophosphataemia. This suggests that changes in circulating levels of 1,25(OH)2D3 were not necessary for the increased efficiency of intestinal phosphorus absorption seen in phosphorus-depleted hypophosphataemic sheep, and may explain why there is no increase in efficiency of intestinal calcium absorption in phosphorus depleted sheep. Increases in phosphataemia induced acutely by intravenous phosphate infusion for 3 h also had no effect on plasma 1,25(OH)2D3 concentration. It is concluded that in the sheep, unlike non-ruminant animals, chronic hypophosphataemia does not increase plasma 1,25(OH)2D3 concentrations and plays no physiological role in regulating its production or metabolism.

Raised levels of calcium-binding protein in plasma following insulin-induced hypoglycaemia in the pig.

Insulin-induced hypoglycaemia in the pig elicited sharp increases in the plasma concentrations of vitamin D-dependent calcium-binding protein (CaBP) and cortisol and a decrease in plasma inorganic phosphate. Glucose infusion following insulin administration abolished the increases in plasma CaBP and cortisol in response to insulin and reduced the hypophosphataemia. The percentage increases in plasma CaBP and cortisol in response to insulin-induced hypoglycaemia were reduced when the pigs were fed a low-calcium diet, but the hypophosphataemic response was similar. We conclude that insulin-induced hypoglycaemia leads to increased plasma CaBP in pigs fed a normal calcium diet, which is associated with the hypoglycaemia rather than being a direct effect of insulin. We therefore suggest that plasma CaBP may represent more than a mere uncontrolled leak from its sites of storage.

The effects of betamethasone on plasma and intestinal calcium binding protein and on 25-hydroxyvitamin D3 metabolism in the pig.

Betamethasone (50 micrograms/kg body weight/day) given to young pigs reduced calcium absorption, growth and plasma vitamin D dependent calcium binding protein (CaBP) concentration. No changes occurred in plasma 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and intestinal CaBP concentrations. 1,25(OH)2D3 (0.1 microgram/kg body weight/day) given with betamethasone increased calcium absorption although growth and plasma CaBP concentrations remained low. Intestinal CaBP levels remained unchanged. Plasma CaBP concentrations were not consistently related to intestinal CaBP or calcium absorption in the presence of betamethasone. We conclude that betamethasone-induced depression of calcium absorption was not mediated by alterations in intestinal CaBP, but the mechanism remains obscure.

Vitamin D-dependent rickets type I in pigs.

We have bred a strain of pigs with an inherited condition of hypocalcaemic rickets, transmitted by an autosomal-recessive mechanism. Homozygous (affected) piglets grew at half the rate of their heterozygous (clinically normal) littermates, and developed profound hypocalcaemia with severe secondary hyperparathyroidism and hypophosphataemia by 8 weeks of age. In the hypocalcaemic piglets, plasma 1,25-dihydroxyvitamin D levels were low or undetectable, and 24,25-dihydroxyvitamin D3 levels were also reduced despite 25-hydroxyvitamin D3 levels being 2-fold higher. There was no detectable 25-hydroxyvitamin D3-1- or -24-hydroxylase enzyme activity in renal homogenates prepared from affected animals. Plasma and intestinal calcium-binding protein levels were reduced in the hypocalcaemic piglets. Sucrose density gradient analysis of intestinal cytosol, prepared in high-salt buffer, revealed the presence of a similar amount of a specific less than 4.2S 1,25-dihydroxyvitamin D3 binder in both groups of piglets. Administration of pharmacological doses of vitamin D3 to affected animals reversed the hypocalcaemia. We conclude that this strain of pigs has vitamin D-dependent rickets type I.