Joanne E. McKenzie

Iron deficiency and risk factors for lower iron stores in 6-24-month-old New Zealanders.

Objective: To determine the prevalence of biochemical iron deficiency and identify factors associated with ferritin levels among 6–24-month-old urban South Island New Zealand children.Design: Cross-sectional survey conducted from May 1998 to March 1999.Setting: The cities of Christchurch, Dunedin and Invercargill.Subjects: A total of 323 randomly selected 6–24-month-old children participated (response rate 61%) of which 263 provided a blood sample.Methods: A complete blood cell count, zinc protoporphyrin, serum ferritin and C-reactive protein were measured on nonfasting venipuncture blood samples, 3-day weighed food records and general questionnaire data were collected.Results: Among children with C-reactive protein<10u2009mg/l (n=231), 4.3% had iron deficiency anaemia, 5.6% had iron deficiency without anaemia, and 18.6% had depleted iron stores, when a ferritin cutoff of ≤12u2009g/l was used. Age (negative), sex (girls>boys), ethnicity (Caucasian>non-Caucasian), weight-for-age percentiles (negative) and birth weight (positive) were associated with ferritin after adjusting for infection and socioeconomic status. When current consumption of iron fortified formula and >500u2009ml of cows milk per day were included, these were associated with a 22% increase and 25% decrease in ferritin, respectively (R 2=0.28).Conclusion: The presence of suboptimal iron status (29%) among young New Zealand children is cause for concern, even though severe iron deficiency is rare, because children with marginal iron status are at risk of developing severe iron deficiency if exposed to a physiological challenge.Sponsorship: Health Research Council of New Zealand.

Lifestyle factors associated with glycaemic control and body mass index in older adults with diabetes

Objective: To investigate the relations between lifestyle factors (diet and exercise), glycated haemoglobin (HbA1c) and body mass index (BMI) in older adults with diabetes.Design and setting: A community hospital-based cross-sectional study of 150 noninstitutionalized, ambulatory adults (≥65u2009y) with diabetes, residing within New Zealands Kapiti region.Subjects: Patients were recruited from all general practices; two diabetes clinics; local diabetes society and through advertisements in community newspapers. A total of 211 eligible people were identified, but 60 refused to participate and one withdrew. In all, 150 people completed the study (71% participation rate).Methods: Nutrient intakes were calculated by a food-frequency questionnaire. Physical activity was assessed by interview using a validated questionnaire. Medical history and demographic data were obtained by interview or self-completed questionnaires; height, weight and HbA1c were measured. Multivariate models using bootstrapping and stepwise linear regression were used to select factors associated with HbA1c and BMI.Results: Each five-unit increase in energy from dietary saturated fat and five-unit increase in BMI were associated with 6% (95% confidence interval=2–10%; P=0.004) and 4% (0.3–7%; P=0.031) increases in HbA1c, respectively. For females with moderate, compared with low overall activity, there was a 14% (7–20%; P=0.000) reduction in BMI while for males the reduction was only 5% (−1–11%; P=0.116). BMI decreased 5% (2–9%; P=0.004) with each 10-y increase in age, while a five-unit increment in energy from dietary sucrose was associated with a 6% (1–11%; P=0.025) increase in BMI.Conclusions: Reducing dietary saturated fat and excess body weight may be useful means of improving glycaemic control in older adults with diabetes. Increasing physical activity and reducing energy from dietary sucrose may assist weight control, the former particularly in women.Sponsorship: University of Otago (New Zealand) Postgraduate Award. Ecolab™ sponsored New Zealand Dietetic Association Award.