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Juan A Rull

Publications and source records attributed to Juan A Rull.

At least 19 recordsLinked to original sources
PubMed2007

Radioiodine treatment in autoimmune hyperthyroidism: analysis of outcomes in relation to dosage.

BACKGROUND: Controversy exists regarding the optimal dose of radioiodine ((131)I) therapy in autoimmune hyperthyroidism (i.e., Graves' Disease). METHODS: In order to evaluate the efficacy and safety of high dose (131)I therapy in autoimmune hyperthyroidism, a retrospective review of patients who received (131)I therapy for Graves' disease from 1980 to 2000 in the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City was carried out. RESULTS: The study population consisted of 596 autoimmune hyperthyroid patients with a mean age of 35 years. The mean follow-up period was 10.31 +/- 2.37 years. Remission of hyperthyroidism occurred in 81.9%, persistent hyperthyroidism was recorded in 14.4% and recurrence in 3.7%. (131)I doses of 5-9 mCi (185-333 MBq) and > or =20 mCi (> or =740 MBq) were associated with remission rates of 65.5% and 87.7% respectively. Remission occurred earlier and more often with high doses of (131)I. The high-dose group (20-30 mCi [740-1110 MBq]) had the lowest rate of persistence (9.7, 27.5 and 34.3%, for 20-30 [740-1110 MBq], 10-14 [370-518 MBq] and 5-9 [185-333 MBq] mCi, respectively p <0.05) and hypothyroidism occurred earlier in this group (p = 0.05). CONCLUSIONS: Remission of autoimmune hyperthyroidism is more likely with doses of 20-30 mCi (740-1110 MBq).

Adult↗
PubMed2006

Genetic heterogeneity of autosomal dominant hypercholesterolemia in Mexico.

BACKGROUND: Familial hypercholesterolemia (FH) and familial defective apolipoprotein B-100 (FDB) are relatively common lipid disorders caused by mutations of the low-density lipoprotein receptor (LDLR) and apolipoprotein B (apoB) genes, respectively. A third locus on chromosome 1p34.1-p32 was recently linked to FH and the responsible gene has been identified [protein convertase subtilisin/kexin type 9 (PCSK9)]. METHODS: We assessed the contribution of the LDLR, apoB, and PCSK9 genes as cause of FH in Mexico. Forty six unrelated probands, as well as 68 affected and 60 healthy relatives, were included. RESULTS: All index cases were diagnosed as having heterozygous autosomal dominant FH. Seventeen of the 46 index cases had LDLR gene mutations, four of which were novel (Fs92ter108, C268R, Q718X, and Fs736ter743); and only one patient had an apoB mutation (R3500Q). We sequenced the PCSK9 gene in the remainder of the 28 probands with no identified LDLR or APOB gene defects; however, no PCSK9 mutations were found, including one large kindred with positive linkage to the 1p34.1-32 locus (multipoint LOD score of 3.3) and two small pedigrees. Linkage was excluded from these three loci in at least four kindreds suggesting that other yet uncharacterized genes are involved. CONCLUSIONS: Our results underline substantial genetic heterogeneity for FH in the Mexican population.

Adult↗
PubMed2006

Design and validation of a population-based definition of the metabolic syndrome.

OBJECTIVE: The National Cholesterol Education Program (NCEP) definition of the metabolic syndrome was modified to be described as a continuous variable and adapted to the characteristics of a Hispanic population. RESEARCH DESIGN AND METHODS: Age/sex population percentiles for every component of the NCEP criteria were included in this approach using population-based data from a Mexican nationwide survey (2,158 subjects). One point was given per decile for every component. The total number of points accumulated was used to classify subjects. The predictive power for incident diabetes was evaluated using the 7-year follow-up results of the Mexico City Diabetes Study. RESULTS: Our population-based method had a significantly better prognostic power compared with the original and the updated NCEP definitions (area under the receiver operating characteristic curve 0.746 vs. 0.697 and 0.723, respectively, P < 0.05). Using individuals with </=1 component of the NCEP definition as reference, the odds ratio was greater in the upper quartile of the points scale (>/=39 points) (12.71 [95% CI 5.67-28.49]) compared with that calculated for the original (9.52 [4.69-19.31]) and the updated (11.14 [5.33-23.30]) NCEP criteria. The major advantage of our approach is the detection of subjects at the extremes of the range of diabetes risk and the ability to estimate this risk as a continuum. CONCLUSIONS: Our method adapts the NCEP criteria to the characteristics of a Hispanic population. It improves the predictive power of the NCEP criteria for future diabetes.

Adult↗
PubMed2004

Psychosocial factors associated with poor diabetes self-care management in a specialized center in Mexico City.

To examine the relationship between demographic, clinical and psychosocial variables and diabetes self-care management in Mexican type 2 diabetic patients. Cross-sectional study of 176 consecutive patients with type 2 diabetes aged 30-75 years, attending a tertiary health-care center in Mexico City. A brief medical history and previously validated questionnaires were completed. The study group consisted of 64 males/112 females, aged 55 +/- 11 years, mean diabetes duration of 12 +/- 8 years and HbA1c of 9.0 +/- 2.0%, 78.4% reported following the correct dose of diabetes pills or insulin, 58% ate the recommended food portions, and 44.3% did exercise three or more times per week. A good adherence to these three recommendations was observed in only 26.1% of the patients. These patients considered as a group were characterized by a greater knowledge about the disease (P < 0.00001), regular home blood glucose monitoring (P < 0.01), an inner perception of better diabetes control (P = 0.007), good health (P = 0.004) and better communication with their physician (P < 0.02). A poor adherence to two or the three main diabetes care recommendations was associated with a depressive state (OR 2.38, 95% CI 1.1-4.9, P < 0.01) and a history of excessive alcohol intake (OR 4.03, 95% CI 1.1-21.0, P = 0.03). Poor adherence to standard diabetes care recommendations is frequently observed in patients with type 2 diabetes attending a specialized health care center in Mexico City. Depression must be identified and treated effectively.

Adult↗
PubMed2004

Familial combined hyperlipidemia: controversial aspects of its diagnosis and pathogenesis.

Familial combined hyperlipidemia is the most frequent cause of primary dyslipidemia in Mexico. Its manifestations include hypercholesterolemia, hypertriglyceridemia, or a combination of both. Despite its high frequency, a proper diagnosis is rarely made. Assessment of the lipid profiles of at least three first-degree relatives is necessary. The diagnosis of familial combined hyperlipidemia in a family not only leads to the identification of other affected family members but, more important, allows cardiovascular risk stratification of those affected. Prospective studies have confirmed the atherogenicity of the disease. A critical review of the current literature in this field is presented in this article. Although three screenings of the genome have been completed, the genes responsible for this disorder have not been identified. Limitations with respect to the characterization of affected subjects and the heterogeneity of the disease are among possible explanations. However, familial combined hyperlipidemia, because of its high prevalence, must be given greater priority. It represents a great challenge for physicians involved in the treatment of dyslipidemic patients.

Apolipoproteins B↗
PubMed2004

The differential effects of metformin on markers of endothelial activation and inflammation in subjects with impaired glucose tolerance: a placebo-controlled, randomized clinical trial.

The effect of metformin (1000 mg twice a day) on markers of endothelial activation, inflammation, and coagulation was investigated in subjects with impaired glucose tolerance (IGT) in a 16-wk, randomized, placebo-controlled, double-blind study. Soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, C-reactive protein, TNFalpha, von Willebrand factor, and tissue plasminogen activator were measured at baseline and at the end of the trial. Subjects with IGT (n = 55, 14 males and 41 females), aged 48.4 +/- 9.6 yr with a body mass index of 31.4 +/- 5.6 kg/m(2), were studied. All participants followed a 1-month stabilization period in their diet and physical activity. Afterward, 29 subjects were assigned to the treatment group and 26 to the control group. A significant reduction in weight, fasting plasma glucose, soluble intercellular adhesion molecule (306 +/- 75 vs. 268 +/- 61 ng/ml, P = 0.029), soluble vascular cell adhesion molecule (595 +/- 114 vs. 508 +/- 126 ng/ml, P = 0.006), and von Willebrand factor (124 +/- 34 vs. 94 +/- 34%, P = 0.001) was seen in the treatment group, whereas tissue plasminogen activator, TNFalpha, and C-reactive protein levels did not change. No change was seen in the control group. Thus, metformin improves the plasma levels of some markers of endothelial activation and coagulation in subjects with IGT, whereas it has no effect on markers of inflammation.

Adult↗
PubMed2002

Prevalence and characteristics of early-onset type 2 diabetes in Mexico.

OBJECTIVE: To investigate the prevalence and characteristics of patients with type 2 diabetes diagnosed before the age of 40 years (early-onset disease) in a nationwide, population-based study. METHODS: Using a multistage sampling procedure, we enrolled a representative sample of Mexican urban adults aged 20 to 69 years. Weight, height, blood pressure, and plasma levels of glucose, insulin, and other metabolic parameters were measured in all subjects. RESULTS: We identified 993 subjects with type 2 diabetes, including 143 subjects aged 20 to 39 years (14% of those with diabetes). Subjects with early-onset diabetes had a greater prevalence of obesity and higher plasma insulin and lipid levels than did age-matched controls, and a greater prevalence of high-density lipoprotein cholesterol levels <35 mg/dL and severe hypertriglyceridemia than did older subjects with diabetes. Those (n = 32) with a normal body mass index (20 to 25 kg/m(2)) tended to have insulin deficiency as the main abnormality, whereas the "metabolic syndrome" characterized the remaining 111 subjects with early-onset diabetes. CONCLUSION: Most patients with early-onset type 2 diabetes in Mexico are obese or overweight, suggesting that obesity treatment and prevention programs may be effective in reducing the prevalence of this disease.

Adult↗
PubMed2002

Lack of agreement between the plasma lipid-based criteria and apoprotein B for the diagnosis of familial combined hyperlipidemia in members of familial combined hyperlipidemia kindreds.

Our objective was to analyze the concordance between abnormally high-cholesterol and triglyceride concentrations and increased apoliprotein B (apoB) concentrations for considering subjects as affected in familial combined hyperlipidemia (FCHL) kindreds. Twenty-two FCHL families (n = 217) were included. There was a lack of agreement in the identification of the abnormal subjects when several cholesterol- and triglyceride-based criteria were compared against various apoprotein B-based criteria. The agreement, measured as kappa coefficients, between 14 lipid-based criteria and 8 apoB concentrations is reported. For the most frequently used criterion (> or = 90th percentile for cholesterol or triglyceride concentrations), the agreement was low for all apoB levels (kappa, 0.42 to 0.49). A concentration of triglycerides > or = 150 mg/dL and cholesterol > or = 200 mg/dL was the only criterion with a kappa value above 0.6; the acceptable agreement was found with an apoB concentration > or = 120 mg/dL (kappa = 0.604). In conclusion, the data reported here clearly show that a large degree of diagnostic uncertainty exists in the categorization as normal or abnormal of members of FCHL kindred. Different diagnostic criteria would result in conflicting results. This is a critical issue, depending on the diagnostic criteria used, completely different conclusions could result from the linkage analysis in the FCHL studies.

Adult↗
PubMed2002

Apolipoprotein B and A-I distribution in Mexican urban adults: results of a nationwide survey.

The apolipoprotein (apo) B and A-I distribution found in a survey performed in 417 Mexican cities is described. Information was obtained from 15,607 subjects aged 20 to 69 years. In this report, only samples obtained after a 9- to 12-hour fast were included (1,674 cases, 652 men and 1,022 women). The population is representative of the Mexican urban adults. Mean lipid concentrations were: cholesterol,182.7 mg/dL; triglycerides, 213 mg/dL; high-density lipoprotein (HDL) cholesterol, 38.3 mg/dL; and low-density lipoprotein (LDL) cholesterol, 116 mg/dL. The mean concentration of apo B was 77.8 +/- 25.9 mg/dL and 71 +/- 22.8 in men and women, respectively. A continuous increase of apo B was observed as subjects got older. A tendency to decrease after age 60 was observed in men, but not in women. The body mass index (BMI) is a major determinant for the apo B concentrations. The 90th percentile of the apo B concentration identifies a similar proportion of abnormal subjects than the LDL cholesterol concentration of 160 mg/dL. The 120 mg/dL concentration, upper normal limit level used in other populations, identified as abnormal only 3.8% of the cases. Regardless of the lipid abnormality, an apo B above the 90th percentile was associated with higher levels of glucose, cholesterol, triglycerides, and non-HDL cholesterol, despite a similar age and BMI. The overall mean concentration of apo A-I was 122.3 +/- 31 mg/dL and 129 +/- 34 in men and women, respectively. In conclusion, our data show that the apo B and apo A-I concentrations in Mexican urban adults are lower compared with the levels reported in other ethnic groups. Previously used reference ranges are not useful in the population report herein. These observations strengthen the need for obtaining data in population-based studies worldwide.

Adult↗
PubMed1985

Nortriptyline and fluphenazine in the symptomatic treatment of diabetic neuropathy. A double-blind cross-over study.

A controlled clinical trial on the efficacy of a nortriptyline-fluphenazine combination was carried out in patients with painful diabetic polyneuropathy. A visual analog scale was used to evaluate the relief of pain or paresthesia. Significant relief of both pain and paresthesia was obtained with this combination. The differences were statistically significant. Side effects were frequent but not usually severe enough to lead to cessation of these medications.

Adult↗
PubMedDate not supplied

High prevalence of metabolic syndrome in Mexico.

BACKGROUND: Our objective was to describe the prevalence of the metabolic syndrome using World Health Organization (WHO) and National Cholesterol Education Program (NCEP-III) definitions in a population-based survey. METHODS: We performed an analysis of data from a Mexican nationwide, population-based study. The population was composed of 2,158 men and women aged 20-69 years sampled after a 9-12 h fasting period. Prevalence of the metabolic syndrome as defined by the NCEP-III definition and WHO criteria was estimated and case characteristics were assessed. RESULTS: Age-adjusted prevalence was 13.61% for WHO criteria and 26.6% for the NCEP-III definition. Prevalence was 9.2 and 21.4%, respectively, in subjects without diabetes. Thirty five percent of affected cases were <40 years of age. In addition to criteria used for diagnosis, ca. 90% were either overweight or obese. In cases detected using WHO criteria, antihypertensive treatment or blood pressure reading >140/90 was found in 61.8%. The proportion of subjects who qualified for hypolipemiant treatment was lower: lifestyle modifications were needed in 42.1% and drug therapy was required in 18.9%. The same trends were found for cases detected using the NCEP definition. CONCLUSIONS: Prevalence of the metabolic syndrome in Mexico is high. A large proportion of affected cases qualify for preventive actions for complications of the metabolic syndrome (i.e., weight loss, antihypertensive or hypolipemiant treatment). These results provide data for planning therapeutic programs for Mexican patients with the metabolic syndrome.

Adult↗
PubMedDate not supplied

The metabolic syndrome: a concept hard to define.

The metabolic syndrome integrates, in a single diagnosis, the manifestations of insulin resistance that may lead to increased cardiovascular morbidity and precedes type 2 diabetes. Here we discuss the strengths and limitations of the definitions of the metabolic syndrome and the epidemiology of the syndrome including information from non-Caucasian populations. The definitions proposed by the World Health Organization (WHO) and the National Cholesterol Education Program (NCEP) are the most frequently used. The relative risk of having long-term complications is greater for the WHO definition; this is explained by the inclusion of the insulin resistance criteria. The cut-off points used in these definitions should be, but are not, adjusted for ethnicity; as a result, in non-Caucasian subjects, there is lack of agreement among these criteria. In a Mexican population-based survey the prevalence was 13.61% using the WHO definition and 26.6% using the NCEP-III criteria. Cases identified by the WHO criteria had a more severe form of the disease. We propose that the metabolic syndrome should be viewed as a progressive long-term process that leads to major complications. Its definition should reflect the continuous nature of the disease; the categorical approach of the current criteria oversimplifies the complexity of the syndrome. The threshold for defining abnormality should be based on the associated risk of the identified phenotype. Refinement of the definition of both affected and nonaffected subjects is required. The available definitions include, in each of these categories, heterogeneous groups with a broad range of risk of future complications.

Adult↗
PubMedDate not supplied

Epidemiology of type 2 diabetes in Mexico.

The epidemiology of diabetes in Mexico is reviewed. In less than four decades, diabetes has become the main health problem in Mexico. It is the principal cause of death in women and the second among men since the year 2000. It is the primary cause of premature retirement, blindness, and kidney failure. By the year 2025, close to 11.7 million Mexicans are expected to be diagnosed with diabetes. In the year 2000, diabetes was the 11th most frequent cause of hospitalization but the second most common cause of hospital mortality. The number of cases reported in children has also increased since 1995. The results of population-based, nationwide surveys have detected a 25% increment over a 7-year period. Fourteen percent of people with diabetes are <40 years of age, and a large proportion of patients have other conditions that determine the appearance of macrovascular complications and kidney failure. In addition, many cases do not reach treatment goals. In conclusion, the growing number of cases and the significant health burden imposed on affected subjects makes diabetes a disease that needs to be prevented. Well-planned strategies are urgently needed to modify the lifestyle of the population and to increase their physical activity. In addition, an enormous effort will be required to educate the population and physicians to improve the diagnosis and treatment of patients with diabetes.

Adult↗
PubMedDate not supplied

Insulin therapy: current alternatives.

In normal humans, blood glucose and insulin are maintained within a narrow range despite wide variations in physical activity and dietary intake. At present, reproducing this pattern is an impossible task in type 1 diabetes and extremely difficult in type 2 DM. New approaches using novel insulin analogs and routes of administration, attempting to replicate physiological insulin secretion in diabetic patients, are improving the profiles of glucose levels and, thus, the quality of life. Ultra-short-acting insulin analogues and ultra-long-acting analogues are being used for prandial and basal effects with better results, lower prevalence of hypoglycemia, and, hopefully, fewer chronic complications. Non-invasive routes of administration are being developed. The most promising appears to be inhaled insulin according to studies demonstrating excellent control, apparently without significant side effects, although in relatively short-term trials. Longer-term studies to assure the safety are still necessary before recommending its extended use. This is an extensive, up-to-date review of recent advances in insulin therapy.

Administration, Oral↗
PubMedDate not supplied

Localization of parathyroid adenomas by (99m)Tc-sestamibi scanning: upper neck versus lower neck lesions.

OBJECTIVE: To assess the diagnostic properties of (99m)Tc-sestamibi scanning (dual-phase technique) in patients with primary hyperparathyroidism and to establish the overall efficacy of this imaging technique for localization of an adenoma. METHODS: The medical records of all 131 patients who underwent parathyroid scanning in a tertiary care center between January 1997 and December 2002 were reviewed. The surgical findings were used as the "gold standard" for the diagnosis of parathyroid pathologic conditions. RESULTS: Primary hyperparathyroidism was diagnosed in 87 of the 131 patients (66.4%); of these, 76 underwent surgical treatment. In 44 patients, sestamibi scanning was also done for conditions other than primary hyperparathyroidism. (99m)Tc-sestamibi scanning had a sensitivity of 79.1%, a specificity of 86.7%, a positive predictive value of 88.3%, a false-positive rate of 11.6%, and a false-negative rate of 23.3% for the diagnosis of parathyroid adenoma. Despite the apparent high sensitivity of this scanning technique, only 58.2% of the adenomas were found intra-operatively at the location predicted by the scan. Lesions in the upper neck area were missed more frequently by sestamibi scanning than were those in the lower neck area (13 of 32 versus 1 of 35, respectively) (P<0.05). CONCLUSION: Preoperative localization of parathyroid adenomas with use of (99m)Tc-sestamibi scanning showed a limited capacity to reveal their precise location. Thus, such scans must be complemented with other studies, such as intraoperative ultrasonography and rapid parathyroid hormone assay, to ensure a successful excision if a limited surgical procedure is planned.

Adenoma↗
PubMedDate not supplied

Diagnostic challenge of glucagonoma: case report and literature review.

OBJECTIVE: To report the diagnostic difficulties encountered in a case of glucagonoma. METHODS: We provide a literature review and present the clinical findings, pertinent laboratory data, and results of related studies in a patient with a glucagonoma. RESULTS: A 54-year-old-man, with no relevant history of endocrine disorders, presented to the hospital with a 5-year history of recurrent stomatitis and glossitis, a more recent weight loss of 11.5 kg, and recurrent pruritic maculae on the scalp in conjunction with raised erythematous maculae in the scrotal region and perineum that gradually migrated to the distal extremities, becoming bullous and painful. The patient was hospitalized, and because of the dermatologic findings suggestive of necrolytic migratory erythema, the presence of a glucagonoma was suspected. His blood glucose levels were in the normal range. Glucagon levels were found to be elevated, and imaging studies confirmed the presence of an enlarged mass in the pancreatic tail, without evidence of extension to surrounding structures. Liver metastatic lesions were also excluded. After surgical removal of the tumor, the skin and oral mucosal lesions disappeared spontaneously. The histologic appearance and immunohistochemical staining results confirmed the diagnosis of a glucagonoma. Subsequently, all related symptoms resolved, and the glucagon levels normalized. CONCLUSION: The diagnosis of glucagonoma is often delayed. Clinicians should be aware of the unusual initial manifestations of this tumor and the potential for less than a full spectrum of the characteristic features of the glucagonoma syndrome.

Erythema↗