Search PubMed⌕ Search

Biomedical subjects

I M Baird

Publications and source records attributed to I M Baird.

At least 19 recordsLinked to original sources
PubMed2000

Repeated dose study of sucralose tolerance in human subjects.

Two tolerance studies were conducted in healthy human adult volunteers. The first study was an ascending dose study conducted in eight subjects, in which sucralose was administered at doses of 1, 2. 5, 5 and 10mg/kg at 48-hour intervals and followed by daily dosing at 2mg/kg for 3 days and 5mg/kg for 4 days. In the second study, subjects consumed either sucralose (n=77) or fructose (50g/day) (n=31) twice daily in single blind fashion. Sucralose dosage levels were 125mg/day for weeks 1-3, 250mg/day during weeks 4-7, and 500mg/day during weeks 8-12. No adverse experiences or clinically detectable effects were attributable to sucralose in either study. Similarly, haematology, serum biochemistry, urinalysis and EKG tracings were unaffected by sucralose administration. In the 13-week study, serial slit lamp ophthalmologic examination performed in a random subset of the study groups revealed no changes. Fasting and 2-hour post-dosing blood sucralose concentrations obtained daily during week 12 of the study revealed no rising trend for blood sucralose. Sucralose was well tolerated by human volunteers in single doses up to 10mg/kg/day and repeated doses increasing to 5mg/kg/day for 13 weeks. Based on these studies and the extensive animal safety database, there is no indication that adverse effects on human health would occur from frequent or long-term exposure to sucralose at the maximum anticipated levels of intake.

Administration, Oral↗
PubMed1994

Obesity and insurance risk: the insurance industry's viewpoint.

Obesity is regarded by insurance companies as a substantial risk for both life and disability policies. This risk increases proportionally with the degree of obesity. Mortality statistics for life insurance were the earliest indicator that the cost of obesity to the individual was a decreased life span and increased illness, particularly that affecting the cardiovascular and musculoskeletal systems. The prevalence of coronary heart disease rises with increases in the body mass index in both men and women. Cigarette smoking greatly augments these risks in both sexes. Hypertension and diabetes are very common in obese persons and add further to the risks of vascular disease. Abdominal obesity (when the abdominal girth measured round the umbilicus exceeds the maximum measurement round the hips) is correlated with the risk of cardiac disease and stroke, independently of bodyweight. Insurance companies consider abdominal obesity as unfavourable and rate it accordingly. Obesity (even that of moderate degree) greatly increases the chances of disability due to cardiovascular disease or musculoskeletal illness. In one study of 51 522 adult Finns, 25% of disability pensions in women were found to result directly from obesity. Obesity causes increased health expenditure, decreased life span and productivity, and premature retirement. Insurance companies are compelled to build these risks into their policies. However, because the excess mortality occurs late in mild to moderate obesity, some companies may minimise this risk for life policies that mature early.

Cardiovascular Diseases↗
PubMed1993

Rapid enzyme diagnosis of patients with acute chest pain reduces patient stay in the coronary care unit.

We have studied the effect of early exclusion of myocardial infarction using rapid biochemical diagnosis on the management of patients admitted to the coronary care unit of a district general hospital. Diagnosis was based on the rate of creatine kinase increase in serial samples obtained over the 8 h following admission. For an initial 3-month familiarization period serial creatinine kinase results were made available at the end of working day to supplement clinical management, supported by our traditional protocol of admission and daily enzyme determinations. Subsequently, for a 4-month period, the admission to 8 h serial values were provided by 1100 h each day and usually within 24 h of admission. There was a net reduction in length of stay on the coronary care unit to a median 2 days (n = 66) compared with 3 days (n = 41) for patients without further cardiac symptoms or electrocardiographic changes suggestive of ischaemia or infarction. This change was significant, P = 0.007, Mann-Whitney U test. Reversion to the original protocol of daily enzyme estimations resulted in an increase in the length of stay on the coronary care unit back to a median of 3 days for this patient group. Rapid diagnostic protocols, applied within routine clinical practice, have the potential for real reduction in coronary care unit stay.

Aspartate Aminotransferases↗
PubMed1992

Improvement in left ventricular function after rapid weight loss in obesity.

The effect of rapid weight reduction on left ventricular function and blood pressure was studied in 34 obese subjects, who all weighed more than 30% above their ideal body weight. Subjects with co-existing hypertension (N = 15) and proven coronary artery disease (N = 9) were included to assess contributions from these factors. Blood pressure (BP) was measured both indirectly and by direct ambulatory intra-arterial methods. Radionuclide ventriculography was performed at rest and at exercise, before and after dieting, which was supervised in hospital (daily intake 330 kCal day-1 for 4 weeks). Dieting induced a weight loss of (mean +/- SD) 9.6 +/- 3.5 kg (P less than 0.0001) in the whole group. The mean daytime intra-arterial blood pressure fell from 157 +/- 23/90 +/- 15 to 144 +/- 21/85 +/- 13 mmHg (P less than 0.0001). The fall in ambulatory intra-arterial diastolic blood pressure did not reach significance in the normotensive and ischaemic groups. The mean resting left ventricular ejection fraction (LVEF) in the whole group showed a significant reduction after weight loss from 61 +/- 10% to 56 +/- 6% (P less than 0.005). Although the individual groups showed a fall in LVEF, the effect was most marked in the hypertensive group, from 65 +/- 9% to 57 +/- 5% (P less than 0.002). Before dieting none of the groups achieved a 'normal' 5% rise in LVEF above basal in response to exercise, the hypertensive and the ischaemic groups both showing non-significant falls. This phenomenon was, however, reversed after weight loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Early diagnosis of acute myocardial infarction by CK-MB mass measurements.

We have studied the changes in creatine kinase (CK) and creatine kinase MB (CK-MB) activity and concentration for the diagnosis of acute myocardial infarction in 73 patients admitted to the coronary care unit with cardiac symptoms of 12 h duration or less. Serial blood samples were obtained for an 8 h period following admission and CK, CK-MB activity and concentration measured. We compared the performance of single values at optimized diagnostic cut-offs and incremental change (log slope) for all three measurements. CK slope combined with CK-MB concentration measurements allowed accurate diagnosis at 4 h from admission. CK-MB concentration determination 8 h from admission (12-16 h from the onset of chest pain) was the most efficient single measurement. Rapid diagnostic categorization and possible selection of patients for thrombolysis in patients with an uncertain admission diagnosis is possible by these techniques.

Adult↗
PubMed1991

Circadian variation and blood pressure: response to rapid weight loss by hypocaloric hyponatraemic diet in obesity.

Ambulatory intra-arterial blood pressure was monitored in 15 obese hypertensive and 10 obese normotensive subjects weighing more than 30% of their ideal body weight. Measurements were taken before and after 1 month in hospital on a diet of 330kCal/day designed to ensure 34 g protein and 65 mmol sodium. Mean +/- s.d. body mass index in the whole group fell from 40.8 +/- 7.6 to 37.2 +/- 7.4 kg/m2 (P less than 0.0001). Daytime intra-arterial blood pressure fell from 176 +/- 19/102 +/- 14 to 162 +/- 16/95 +/- 14 mmHg (P less than 0.0005 and P less than 0.002) in the hypertensive group and from 141 +/- 15/82 +/- 5 to 131 +/- 13/79 +/- 4 mmHg (P less than 0.005 for systolic pressure) in the normotensive group. Circadian variation of systolic intra-arterial blood pressure comparing the mean daytime with the mean night-time blood pressure recordings showed a day-night difference of 27 +/- 10 mmHg in the normotensive group compared with 12 +/- 13 mmHg in the hypertensive group (P less than 0.01). This trend was reversed after weight loss, when the normotensive group showed a day-night difference of 20 +/- 13 mmHg compared with 18 +/- 17 mmHg in the hypertensive group. Thus, circadian variation of systolic intra-arterial blood pressure in the hypertensive group was significantly (P less than 0.01) reduced compared with the normotensive group prior to, but not after, weight loss. These data show that, in obese subjects, weight loss produced a significant reduction in ambulatory intra-arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Metabolic response to low- and very-low-calorie diets.

We compared the metabolic effects of 8-wk caloric restrictions with 330 or 780 kcal/d in two groups of eight obese hospitalized subjects; six control subjects were also studied. Loss of weight but not of adipose tissue was significantly greater on the 330-kcal/d diet. It is likely that dehydration rather than protein catabolism was responsible for additional loss of fat-free mass in the 330-kcal/d group because the nitrogen deficit was not excessive. The thermic response to food was blunted only in the 330-kcal/d group whereas resting oxygen uptake decreased by equal amounts in both groups. There was a decrease in 24-h urinary noradrenaline in the 330-kcal/d group but plasma fT4 was sustained when compared with the 780-kcal/d group; fT3 decreased significantly more quickly in the 330-kcal/d group. There was no correlation between plasma hormone levels and changes in oxygen uptake. Hunger scores were greater on the 780-kcal/d diet.

Adult↗
PubMed1989

Effect of the gastric balloon versus sham procedure on weight loss in obese subjects.

The mechanism by which intragastric balloons induce weight loss is not known, although they may act simply by reducing the amount of food needed to induce satiety. The knowledge that a balloon is present may influence the patients' eating patterns and reduce caloric intake and weight. In order to test whether the balloon or the secondary psychological effect caused weight loss, a double blind balloon versus sham procedure was devised with both groups receiving identical outpatient dietary advice (800 kcal/day). Twenty four obese women with body mass index greater than 30 kg/m2 from an obesity clinic were studied. Twelve had the balloon and 12 the sham procedure. The balloon was removed after three months and the patients were followed for a further three months. There was significantly greater weight loss in the balloon group, mean weight loss (SD) of 7.33 (6.12) kg compared with the sham group, mean weight loss (SD) of 3.33 (3.9) kg (p less than 0.05). Weight loss was not maintained in all patients after balloon removal. Side effects were more common in the balloon group (abdominal pain, nausea, and vomiting) but resolved by the second week. We conclude that the intragastric balloon is a safe and effective method of inducing weight loss in well motivated obese patients.

Adolescent↗
PubMed1989

Diagnosis of acute myocardial infarction from sequential enzyme measurements obtained within 12 hours of admission to hospital.

A prospective study was made of sequential changes in serum creatine kinase (CK) and CK-MB isoenzyme activity within the 12 hours following admission to the coronary care unit on 65 patients with recent chest pain. CK determinations were performed in the laboratory or in the coronary care unit using a dry reagent strip analyser. Slope values for log CK/hour and log CK-MB/hour were calculated, used to confirm or exclude the diagnosis of myocardial infarction, and compared with diagnosis by conventional means. Compared with retrospective diagnosis using all available information, the CK slope had a sensitivity of 100% and a specificity of 94%. This compared with a sensitivity of 94% and specificity of 90% for diagnosis using upper reference limits alone. Determination of CK slope permits very rapid and accurate biochemical confirmation or exclusion of myocardial infarction and the possibility of performing the measurements on the coronary care unit. It additionally offers the prospect of major cost savings resulting from early discharge or transfer from the coronary care unit.

Adult↗
PubMed1989

Cardiovascular changes in obese subjects on very low calorie diet.

The effect of 330 kcal/day diet on cardiac function, blood pressure and cardiac chambers was studied in 34 obese subjects, using radionuclide ventriculography, intra-arterial ambulatory blood pressure recording and echocardiography. The group included 15 hypertensives and nine with coronary artery disease. After 4 weeks dieting, mean body weight fell from 105.6 +/- 22 kg to 96.1 +/- 19 kg (P less than 0.001), mean blood pressure fell from 157 +/- 23 to 144 +/- 21 mmHg systolic and 90 +/- 15 to 85 +/- 13 mmHg diastolic (P less than 0.001). The resting left ventricular ejection fraction after dieting fell significantly only in the hypertensive group (P less than 0.0005). Left ventricular ejection fraction response to exercise was impaired in all subjects. After weight loss this returned to normal except in the coronary artery disease group. There was a significant reduction in left ventricular internal dimensions, left ventricular fraction shortening and left ventricular mass after weight loss.

Adult↗
PubMed1984

Metabolic acidosis induced by carbonic anhydrase inhibitors and salicylates in patients with normal renal function.

Two young patients with unimpaired renal and hepatic function were found to have developed metabolic acidosis after treatment for glaucoma and joint pain with a combination of salicylates and carbonic anhydrase inhibitors in normal doses. Carbonic anhydrase inhibitors appear to interact with salicylates to produce serious metabolic acidosis in patients without the predisposing factors generally considered to constitute risks. It is recommended that treatment combining salicylates and carbonic anhydrase inhibitors is either kept to a minimum or avoided.

Acetazolamide↗
PubMed1983

SeHCAT absorption: a simple test of ileal dysfunction.

A new selenium-labelled synthetic bile salt SeHCAT (taurine conjugate of 23-[75Se]-25-homocholic acid) was assessed as a test of ileal dysfunction in 20 patients with inflammatory bowel disease (IBD). Whole body retention of SeHCAT was compared with tests of vitamin B12 absorption (Schilling test and whole body retention) and the cholylglycine-1-14C breath test and faecal isotope excretion. Clear differentiation, with no overlap was obtained between 10 normal subjects and patients with ileal disease/resection in the SeHCAT 7-day retention results. The Schilling test was more sensitive; enabling discrimination between patients with limited and extensive ileal disease/resection. An unexpected rise in SeHCAT retention was observed in patients with colonic IBD. The 7-day SeHCAT retention is a safe, simple screening test for ileal dysfunction and has practical advantages compared with the Schilling test.

Adult↗