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Biomedical subjects

K G Alberti

Publications and source records attributed to K G Alberti.

At least 37 records · Page 2Linked to original sources

Stroke mortality in urban and rural Tanzania. Adult Morbidity and Mortality Project.

BACKGROUND: Most data for stroke mortality in sub-Saharan Africa are hospital based. We aimed to establish the contribution of cerebrovascular disease to all-cause mortality and cerebrovascular disease mortality rates in adults aged 15 years or more in one urban and two rural areas of Tanzania. METHODS: Regular censuses of the three surveillance populations consisting of 307,820 people (125,932 aged below 15 years and 181,888 aged 15 or more) were undertaken with prospective monitoring of all deaths arising in these populations between June 1, 1992 and May 31, 1995. Verbal autopsies were completed with relatives or carers of the deceased to assess, when possible, the cause of death. FINDINGS: During the 3-year observation period 11,975 deaths were recorded in the three surveillance areas, of which 7629 (64%) were in adults aged 15 years or more (4088 [54%] of these in men and 3541 [46%] in women). In the adults, 421 (5.5%) of the deaths were attributed to cerebrovascular disease, 225 (53%) of these in men and 196 (47%) in women. The yearly age-adjusted rates per 100,000 in the 15-64 year age group for the three project areas (urban, fairly prosperous rural, and poor rural, respectively) were 65 (95% CI 39-90), 44 (31-56), and 35 (22-48) for men, and 88 (48-128), 33 (22-43), and 27 (16-38) for women, as compared with the England and Wales (1993) rates of 10.8 (10.0-11.6) for men and 8.6 (7.9-9.3) for women. INTERPRETATION: We postulate that the high rates in Tanzania were due to untreated hypertension. Our study assessed mortality over a single time period and therefore it is not possible to comment on trends with time. However, ageing of the population is likely to lead to a very large increase in mortality from stroke in the future.

Adolescent↗

Risk of cardiovascular disease measured by carotid intima-media thickness at age 49-51: lifecourse study.

OBJECTIVE: To quantify the direct and indirect effects of fetal life, childhood, and adult life on risk of cardiovascular disease at age 49-51 years. DESIGN: Follow up study of the "Newcastle thousand families" birth cohort established in 1947. PARTICIPANTS: 154 men and 193 women who completed a health and lifestyle questionnaire and attended for clinical examination between October 1996 and December 1998. MAIN OUTCOME MEASURES: Correlations between mean intima-media thickness of the carotid artery (carotid intima-media thickness) and family history, birth weight, and socioeconomic position around birth; socioeconomic position, growth, illness, and adverse life events in childhood; and adult socioeconomic position, lifestyle, and biological risk markers. Proportions of variance in carotid intima-media thickness that were accounted for by each stage of the lifecourse. RESULTS: Socioeconomic position at birth and birth weight were negatively associated with carotid intima-media thickness, although only social class at birth in women was a statistically significant covariate independent of adult lifestyle. These early life variables accounted directly for 2.2% of total variance in men and 2.0% in women. More variation in carotid intima-media thickness was explained by adult socioeconomic position and lifestyle, which accounted directly and indirectly for 3.4% of variance in men (95% confidence interval 0.5% to 6.2%) and 7.6% in women (2.1% to 13.0%). Biological risk markers measured in adulthood independently accounted for a further 9.5% of variance in men (2.4% to 14.2%) and 4.9% in women (1.6% to 7.4%). CONCLUSIONS: Adult lifestyle and biological risk markers were the most important determinants of the cardiovascular health of the study members of the Newcastle thousand families cohort at age 49-51 years. The limited overall effect of early life factors may reflect the postwar birth year of this cohort.

Cardiovascular Diseases↗

Hypertension prevalence and care in an urban and rural area of Tanzania.

OBJECTIVE: To describe the prevalence, detection, treatment and control of hypertension in an urban and rural area of Tanzania. DESIGN: Two linked cross-sectional population-based surveys. SETTING: A middle-income urban district of Dar es Salaam (Ilala) and a village in the relatively prosperous rural area of Kilimanjaro (Shari). PARTICIPANTS: Seven hundred and seventy adults (> 15 years) in Ilala and 928 adults in Shari were studied. RESULTS: Hypertension prevalence (blood pressure > or = 140 and/or 90 mmHg, or known hypertensives receiving anti-hypertensive treatment) was 30% (95% confidence interval, 25.1-34.9%) in men and 28.6% (24.3-32.9%) in women in Ilala, and 32.2% (27.7-36.7%) in men and 31.5% (27.8-35.2%) in women in Shari. Age-standardized hypertension (to the New World Population) prevalence was 37.3% (32.2-42.5%) among men and 39.1% (34.2-44.0%) in women in Ilala, and 26.3% (22.4-30.4%) in men and 27.4% (24A-30.4%) in women in Shari. In both areas, just under 20% of hypertensive subjects were aware of their diagnosis, approximately 10% reported receiving treatment and less than 1% were controlled (blood pressure < 140/90 mmHg). Hypertensive subjects were older, had greater body mass indices and waist: hip ratios, and had more risk factors for hypertension and its complications (smoking, heavy alcohol consumption, physical inactivity, obesity and diabetes) than non-hypertensives. CONCLUSIONS: There is a high prevalence of hypertension in rural and urban areas of Tanzania, with low levels of detection, treatment and control. This demonstrates the need for cost-effective strategies for primary prevention, detection and treatment of hypertension and the growing public health challenge of non-communicable diseases in Sub-Saharan Africa.

Adolescent↗

Age specific prevalence of impairment and disability relating to hemiplegic stroke in the Hai District of northern Tanzania. Adult Morbidity and Mortality Project.

OBJECTIVES: To determine the age specific prevalence of impairment and disability relating to hemiplegic stroke in one rural area of Tanzania. METHODS: During the yearly house to house census of the study population of 148 135 (85 152 aged 15 and over) in August 1994, specific questions were asked to identify those who might be disabled from stroke. People thus identified were subsequently interviewed and examined by one investigator. In those in whom the clinical diagnosis of stroke was confirmed a more detailed interview and examination relating to risk factors and recovery was carried out. RESULTS: One hundred and eight patients, 61 men and 47 women, were identified with a median age of 70 (range 18-100). Median age at first stroke was 65 years. The age specific rates in this study were lower than previous studies in developed countries. All were cared for at home although 23 (21%) were bedbound. CONCLUSIONS: Although prevalence of impairment and disability related to stroke in this population as a whole was low this is mainly explained by the age structure, with less than 6% being aged 65 and over. Age standardised rates for stroke with residual disability were about half those found in previous studies in developed countries. Death from stroke in Africa may be higher but data are limited. With the demographic transition stroke is likely to become a more important cause of disability in sub-Saharan Africa.

Adolescent↗

Continuation of growth hormone (GH) therapy in GH-deficient patients during transition from childhood to adulthood: impact on insulin sensitivity and substrate metabolism.

The appropriate management of GH-deficient patients during transition from childhood to adulthood has not been reported in controlled trials, even though there is evidence to suggest that this phase is associated with specific problems in relation to GH sensitivity. An issue of particular interest is the impact of GH substitution on insulin sensitivity, which normally declines during puberty. We, therefore, evaluated insulin sensitivity (euglycemic glucose clamp) and substrate metabolism in 18 GH-deficient patients (6 females and 12 males; age, 20 +/- 1 yr; body mass index, 25 +/- 1 kg/m2) in a placebo-controlled, parallel study. Measurements were made at baseline, where all patients were on their regular GH replacement, after 12 months of either continued GH (0.018 +/- 0.001 mg/kg day) or placebo, and finally after 12 months of open phase GH therapy (0.016 mg/kg x day). Before study entry GH deficiency was reconfirmed by a stimulation test. During the double-blind phase, insulin sensitivity and fat mass tended to increase in the placebo group [deltaM-value (mg/kg x min), -0.7 +/- 1.1 (GH) vs. 1.3 +/- 0.8 (placebo), P = 0.18; deltaTBF (kg), 0.9 +/- 1.2 (GH) vs. 4.4 +/- 1.6 (placebo), P = 0.1]. Rates of lipid oxidation decreased [delta lipid oxidation (mg/kg x min), 0.02 +/- 0.14 (GH) vs. -0.32 +/- 0.13 (placebo), P < 0.05], whereas glucose oxidation increased in the placebo-treated group (P < 0.05). In the open phase, a decrease in insulin sensitivity was found in the former placebo group, although they lost body fat and increased fat-free mass [M-value (mg/kg x min), 5.1 +/- 0.7 (placebo) vs. 3.4 +/- 1.0 (open), P = 0.09]. In the group randomized to continued GH treatment almost all hormonal and metabolic parameters remained unchanged during the study. In conclusion, 1) discontinuation of GH therapy for 1 yr in adolescent patients induces fat accumulation without compromising insulin sensitivity; and 2) the beneficial effects of continued GH treatment on body composition in terms of decrease in fat mass and increase in fat-free mass does not fully balance the direct insulin antagonistic effects.

3-Hydroxybutyric Acid↗

Impaired fasting glucose: how low should it go?

OBJECTIVE: Impaired fasting glucose (IFG) has been recently introduced as a stage of abnormal carbohydrate metabolism, but the evidence on which its glucose limits (fasting plasma glucose [FPG] 6.1-6.9 mmol/l) are based is not strong. The aim of this study was to determine if 6.1 mmol/l represents a clear cutoff in terms of the risk of future diabetes and in terms of elevated cardiovascular risk factor levels, and to examine the use of other lower limits of IFG. RESEARCH DESIGN AND METHODS: A population-based survey of the island of Mauritius was undertaken in 1987, with a follow-up survey 5 years later. On both occasions, an oral glucose tolerance test was performed and cardiovascular risk factors were measured. RESULTS: Data were available from 4,721 nondiabetic people at baseline, and from 3,542 at follow-up. At baseline, blood pressure, lipids, and obesity increased in a linear fashion with increasing FPG, with no evidence of a threshold effect. The risk of developing hypertension at follow-up was greater for those people with baseline FPG > or =6.1 mmol/l (P<0.001). The risk of developing diabetes at follow-up increased with increasing baseline FPG, but there was little evidence of a threshold near 6.1 mmol/l. CONCLUSIONS: Cardiovascular risk and risk of future diabetes increase continually with increasing FPG, and there is no threshold value on which to base a definition of IFG. If a lower limit of approximately 5.8 mmol/l is used, the category defines a group more similar to the group with impaired glucose tolerance, with regard to total prevalence and the risk of subsequent diabetes.

Adult↗

Features of the metabolic syndrome predict higher risk of diabetes and impaired glucose tolerance: a prospective study in Mauritius.

OBJECTIVE: To assess the independent and joint effects of the components of the metabolic syndrome, including leptin, which is a recently proposed addition to this syndrome, in predicting the cumulative incidence of impaired glucose tolerance (IGT) and diabetes among individuals with normal glucose tolerance. RESEARCH DESIGN AND METHODS: This prospective study involved 2,605 residents of Mauritius with normal glucose tolerance who were followed for 5 years for IGT or diabetes onset in relation to total and regional adiposity (BMI, waist-to-hip ratio [WHR]), fasting and 2-h 75-g oral glucose load glucose and insulin, total and HDL cholesterol, blood pressure, serum uric acid, triglyceride, and leptin levels. RESULTS: A multivariate logistic regression model adjusted for age, sex, ethnicity, and diabetes family history showed a significantly higher linear increase in risk of IGT and diabetes in association with the following variables only: fasting glucose (odds ratio 1.89 [95% CI 1.51-2.34]), 2-h glucose (1.68 [1.50-1.88]), WHR (1.30 [1.10-1.52]), BMI (1.04 [1.00-1.08]), and serum uric acid (1.37 [1.20-1.57]). However, a nonlinear increase was seen with serum triglyceride and plasma leptin concentrations. No risk factors resulted in joint effects that were greater than expected from combining individual effects. CONCLUSIONS: Metabolic syndrome features independently predict a higher risk of diabetes or IGT in normoglycemic subjects but in combination confer no higher-than-expected risk of these outcomes. At higher concentrations of triglycerides and leptin, risk plateaus and even declines slightly.

Adult↗

Heterogeneity of coronary heart disease risk factors in Indian, Pakistani, Bangladeshi, and European origin populations: cross sectional study.

OBJECTIVE: To compare coronary risk factors and disease prevalence among Indians, Pakistanis, and Bangladeshis, and in all South Asians (these three groups together) with Europeans. DESIGN: Cross sectional survey. SETTING: Newcastle upon Tyne. PARTICIPANTS: 259 Indian, 305 Pakistani, 120 Bangladeshi, and 825 European men and women aged 25-74 years. MAIN OUTCOME MEASURES: Social and economic circumstances, lifestyle, self reported symptoms and diseases, blood pressure, electrocardiogram, and anthropometric, haematological, and biochemical measurements. RESULTS: There were differences in social and economic circumstances, lifestyles, anthropometric measures and disease both between Indians, Pakistanis, and Bangladeshis and between all South Asians and Europeans. Bangladeshis and Pakistanis were the poorest groups. For most risk factors, the Bangladeshis (particularly men) fared the worst: smoking was most common (57%) in that group, and Bangladeshis had the highest concentrations of triglycerides (2.04 mmol/l) and fasting blood glucose (6.6 mmol/l) and the lowest concentration of high density lipoprotein cholesterol (0.97 mmol/l). Blood pressure, however, was lowest in Bangladeshis. Bangladeshis were the shortest (men 164 cm tall v 170 cm for Indians and 174 cm for Europeans). A higher proportion of Pakistani and Bangladeshi men had diabetes (22.4% and 26.6% respectively) than Indians (15.2%). Comparisons of all South Asians with Europeans hid some important differences, but South Asians were still disadvantaged in a wide range of risk factors. Findings in women were similar. CONCLUSION: Risk of coronary heart disease is not uniform among South Asians, and there are important differences between Indians, Pakistanis, and Bangladeshis for many coronary risk factors. The belief that, except for insulin resistance, South Asians have lower levels of coronary risk factors than Europeans is incorrect, and may have arisen from combining ethnic subgroups and examining a narrow range of factors.

Adult↗

Twenty-four-hour insulin secretion rates, circulating concentrations of fuel substrates and gut incretin hormones in healthy offspring of Type II (non-insulin-dependent) diabetic parents: evidence of several aberrations.

AIMS/HYPOTHESIS: Insulin resistance is a common feature in relatives of patients with Type II (non-insulin-dependent) diabetes mellitus and abnormalities in beta-cell function can also exist. Insight into non-fasting carbohydrate metabolism in these potentially prediabetic subjects relies almost exclusively on studies in which glucose is infused or ingested or both. We aimed to characterize insulin secretion and aspects of hormonal and metabolic patterns in relatives using a physiological approach. METHODS: We examined profiles of insulin, C peptide, proinsulin, gut incretin hormones and fuel substrates in 26 glucose tolerant but insulin resistant (clamp) relatives and 17 control subjects during a 24-hour period including three meals. RESULTS: During the day plasma glucose was slightly raised in relatives (p < 0.05). Overall insulin secretion calculated on the basis of C peptide kinetics were increased in relatives (p < 0.0005) whereas incremental insulin secretion after all three meals were similar. Peak incremental insulin secretion tended, however, to be reduced in relatives (p < 0.10). Despite considerably increased insulin concentrations in relatives (70 %, p < 0.001), serum NEFA did not differ. Postprandial proinsulin concentrations (p < 0.05), but not proinsulin:insulin ratios, were increased in relatives. After meals concentrations of glucose-dependent-insulinotropic polypeptide (p < 0.05) were increased in relatives. Glucagon-like peptide-1 concentrations were similar. CONCLUSION/INTERPRETATION: Several hormonal and metabolic aberrations are present in healthy relatives of Type II diabetic patients during conditions that simulate daily living. Increased concentrations of glucose-dependent-insulinotropic polypeptide could indicate a beta-cell receptor defect for glucose-dependent-insulinotropic polypeptide in the prediabetic stage of Type II diabetes. Incremental insulin secretion after mixed meals appear normal in relatives, although a trend towards diminished peak values possibly signifies early beta-cell dysfunction. [Diabetologia (1999) 42: 1314-1323]

Adult↗

The amylin analog pramlintide improves glycemic control and reduces postprandial glucagon concentrations in patients with type 1 diabetes mellitus.

To explore further the effects of the human amylin analog pramlintide on overall glycemic control and postprandial responses of circulating glucose, glucagon, and metabolic intermediates in type 1 diabetes mellitus, 14 male type 1 diabetic patients were examined in a double-blind, placebo-controlled, crossover study. Pramlintide (30 microg four times daily) or placebo were administered for 4 weeks, after which a daytime blood profile (8:30 AM to 4:30 PM) was performed. Serum fructosamine was decreased after pramlintide (314+/-14 micromol/L) compared with placebo (350+/-14 micromol/L, P = .008). On the profile day, the mean plasma glucose (8.3+/-0.7 v 10.2+/-0.8 mmol/L, P = .04) and postprandial concentrations (incremental areas under the curve [AUCs] from 0 to 120 minutes) were significantly decreased during pramlintide administration (P < .01 for both) despite comparable circulating insulin levels (359+/-41 v 340+/-35 pmol/L). Mean blood glycerol values were reduced (0.029+/-0.004 v 0.040+/-0.004 mmol/L, P = .01) and blood alanine levels were elevated (0.274+/-0.012 v 0.246+/-0.008 mmol/L, P = .03) after pramlintide versus placebo. Blood lactate concentrations did not differ during the two regimens. During pramlintide administration, the AUC (0 to 120 minutes) for plasma glucagon after breakfast was diminished (P = .02), and a similar trend was observed following lunch. In addition, peak plasma glucagon concentrations 60 minutes after breakfast (45.8+/-7.3 v 72.4+/-8.0 ng/L, P = .005) and lunch (47.6+/-9.0 v 60.9+/-8.2 ng/L, P = .02) were both decreased following pramlintide. These data indicate that pramlintide (30 microg four times daily) is capable of improving metabolic control in type 1 diabetics. This may relate, in part, to suppression of glucagon concentrations. Longer-term studies are required to ascertain whether these findings are sustained over time.

Adult↗