Current British dietary recommendations are to reduce total fat intake to less than 30 % of total energy intake and saturated fat to less than 10 %. The energy lost by this suggested decrease in saturated fat intake is partially replaced by increasing polyunsaturated fat intake. A high intake of total dietary fat has been shown to cause fasting hyperinsulinaemia [1] and to reduce the ability of insulin to suppress endogenous glucose production [2]. Dietary studies have, however, provided conflicting evidence about the beneficial effects of a diet rich in polyunsaturated fat (PUFA diet) on lipoprotein and glucose metabolism.In non-diabetic subjects a PUFA diet could improve total plasma cholesterol concentrations [3] but this could be at the expense of a decrease in HDLcholesterol [4]. On the other hand, in patients with Diabetologia (2002) Abstract Aims/hypothesis. British dietary recommendations are to decrease total fat intake to less than 30 % of daily energy intake and saturated fat to less than 10 %. In practice, it is difficult for people to make these changes. It may be easier to encourage people to switch from a diet rich in saturated fatty acids to one rich in polyunsaturated fatty acids. Methods. A total of 17 subjects ± six people with Type II (non-insulin-dependent) diabetes mellitus, six nonobese and five obese people without diabetes ± were randomised to spend two 5-week periods on a diet rich in saturated or in polyunsaturated fatty acids, in a crossover design. At the start of the study and after each dietary period, we assessed abdominal fat distribution using magnetic resonance imaging, insulin sensitivity using hyperinsulinaemic-euglycaemic clamps and fasting lipid parameters.Results. Dietary compliance, assessed by weekly 3-day dietary records and measurement of biochemical markers, was good. Energy and fat intake appeared to be reduced on the diet rich in polyunsaturated fatty acids although body weights did not change. Insulin sensitivity and plasma low density lipoprotein cholesterol concentrations improved with the diet rich in polyunsaturated fatty acids compared with the diet rich in saturated fatty acids. There was also a decrease in abdominal subcutaneous fat area. Conclusion/interpretation. If this result is confirmed in longer-term studies, this dietary manipulation would be more readily achieved by the general population than the current recommendations and could result in considerable improvement in insulin sensitivity, reducing the risk of developing Type II diabetes. [Diabetologia (2002) 45: 369±377]

Obesity has been associated with dysfunctional postprandial adipose tissue blood flow (ATBF), but it has also been recognized that the interindividual response is highly variable. The present work aimed at characterizing this variability. Fifteen subjects were given 75 g oral glucose, and abdominal subcutaneous ATBF was monitored by the 133 Xe washout method. Determinants of insulin sensitivity based on nonesterified fatty acid (NEFA) suppression after oral glucose administration [ISI(NEFA)] were higher in the top tertile ATBF response group (1.29 ؎ 0.09 vs. 0.90 ؎ 0.08 in the lower tertiles, P ‫؍‬ 0.01). ISI(NEFA) was related to ATBF response (r s ‫؍‬ 0.73, P < 0.002) as well as insulin sensitivity based on postprandial glycemia [ISI(gly), r s ‫؍‬ 0.58, P < 0.05], whereas the homeostasis model assessment (HOMA) index (r s ‫؍‬ ؊0.39, P ‫؍‬ 0.16) was not. The relationship between increase in ATBF and ISI(NEFA) was independent of BMI (P ‫؍‬ 0.015) in multivariate analysis. Subjects with a high ATBF response had significantly higher increase of plasma norepinephrine (P < 0.05), indicating a link between postprandial insulinemia, sympathetic activation, and ATBF response. There is a close relationship between insulin sensitivity and the regulation of postprandial ATBF, independent of adiposity. Impaired regulation of ATBF seems to be another facet of the insulin resistance syndrome.

Type 2 diabetes is a metabolic disorder characterized by chronically elevated blood glucose and high risk of comorbidities. In this article we report a metasynthesis of the 21st-Century qualitative research concerning the self-management of type 2 diabetes. We identified 38 relevant articles (sample size range 6 to 175), which were synthesized through a process of iterative reading and theory development. In this literature, authors argued and assumed that diabetes management is influenced by multiple, complex, competing factors, including interpersonal relations, gender, and sociocultural context. Conversely, self-management was sometimes construed as a facet of individual agency and was accepted uncritically, placing accountability for health with patients themselves. We conclude that a satisfactory account of diabetes care would pay attention to the "inner" world, while acknowledging the social and political conditions in which diabetes-related experiences unfold.

1. We assessed the variation in subcutaneous abdominal adipose tissue blood flow within and between subjects and investigated whether it is correlated with body mass index. 2. We measured body mass index and subcutaneous abdominal adipose tissue blood flow in 38 fasting subjects on the same day and on different days and, in a subgroup of 16 subjects, after a mixed meal. 3. In 190 measurements in the fasted state, subcutaneous abdominal adipose tissue blood flow was significantly more variable between subjects than could be accounted for by the within-subject variation alone. Subcutaneous abdominal adipose tissue blood flow was also significantly more variable between days within subjects than could be accounted for by within-day variation alone. Fasting and post-prandial subcutaneous abdominal adipose tissue blood flow were negatively correlated with body mass index, as was the post-prandial rise in subcutaneous abdominal adipose tissue blood flow. Multiple regression analysis showed that fasting blood flow was not dependent on insulin concentration after allowing for body mass index. There was no correlation between post-prandial subcutaneous abdominal adipose tissue blood flow and insulin concentration. 4. Insulin does not appear to have a direct vasodilatory effect in subcutaneous adipose tissue. Obese subjects have lower fasting and post-prandial subcutaneous abdominal adipose tissue blood flow. This may be because of a blunted response to sympathetic stimulation, or it may be another aspect of the insulin-resistant state.