Publications by authors named "Jinny A Willis"

Geographical variation in the incidence of childhood type 1 diabetes is well documented. Such patterns are thought to give clues to the potential causes of this complex disease. This study examined the urban-rural differences in childhood type 1 diabetes in the Canterbury region of New Zealand between 1980 and 2004.

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Practical values to guide food choices for control of postprandial glycaemia need to refer to entire foods in amounts customarily consumed. We tested an in vitro method for determining the relative glycaemic impact (RGI) of customarily consumed portions of foods. Sugars released during in vitro pancreatic digestion of eighty-three foods were measured as glucose equivalents (GE) per gram of food, adjusted by the glycaemic indexes of the sugars to obtain glycaemic GE (GGE) per gram and multiplied by food portion weight to obtain the GGE contribution of the food portion, its RGI.

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Measurements of blood glucose response to food are highly variable. We determined whether within-individual variability in data for blood glucose responses were reduced if individuals consumed a standard meal 2 hours before testing and investigated the effect of serving size. Blood glucose responses to muesli and macaroni cheese were determined in 13 individuals by taking 2 fasting capillary blood samples.

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There is growing evidence to support a role for infections in the aetiology of childhood type 1 diabetes. However, previous studies suggest that infections can either protect against or initiate type 1 diabetes onset, depending on the timing of exposure. Population mixing has recently been employed as a proxy measure for area-level infectious exposure in childhood diabetes research.

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Glycemic glucose equivalent (GGE) is a measure of the blood glucose response to a defined portion of food. Their calculation requires the measurement of a standard glucose-response curve, with beverages containing 0, 12.5, 25, 50, and 75 g of glucose measured twice each.

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The product of the deleted in colorectal carcinoma (DCC) gene has a role in apoptosis and is a positional candidate for IDDM6, the putative chromosome 18q12-q23 autoimmune disease locus. We hypothesised that a nonconservative substitution (DCC 201 R --> G; nucleotide (nt) 601 C --> G), located in an extracellular immunoglobulin-like domain of DCC, is an aetiological determinant of autoimmunity. We tested this hypothesis by genetically testing the nt 601 C --> G polymorphism for association with three autoimmune phenotypes in a large population-based case-control study.

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Aims: To determine the seasonality of clinical disease onset and month of birth in type 1 diabetes mellitus (DM) in the southern hemisphere.

Patients: Two hundred and seventy-five children with type 1 DM in the South Island of New Zealand were studied. The total live births (91,394) of the same period were used as control data.

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This study examined the epidemiological characteristics of type 1 diabetes mellitus (DM) presenting in Canterbury, New Zealand, between 1970 and 1999. All patients with type 1 DM aged 0-19 years at diagnosis within the Canterbury geographical region were either admitted to the regional hospital or seen acutely as outpatients in clinics at the same institution. Primary ascertainment of incident cases, through notification by the attending physician or paediatrician, began prospectively in 1982.

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