Leon Fogelfeld
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Leon Fogelfeld has a total of 190 co-authors. Here are the top co-authors by number of shared publications:
Arthur B. Schneider
5 shared publicationsBettina Tahsin
Affiliation John H. Stroger Jr., Hospital of Cook County, Chicago, Illinois, United States of America
5 shared publications- Elizabeth B. Lynch
Dept. of Family and Preventive Medicine, Rush University Medical Center, Chicago, USA
3 shared publications Jadwiga Miernik
Division of Endocrinology, Cook County Health & Hospitals System, Chicago, IL
3 shared publicationsMichael Morkos
Division of Endocrinology and Diabetes, John H. Stroger, Jr. Hospital of Cook County and Rush University Medical Center, Chicago, IL, 60612, USA
3 shared publications- Rasa Kazlauskaite
Department of Preventive Medicine, Rush University Medical Center, 1700 W. Van Buren St., Suite 470, Chicago, IL 60612, USA
3 shared publications
Latest Publications
- Open Access
- 2 September 2022
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 17 (9) , e0273724
Tachycardia in hyperthyroidism: Not so common
Objective: The commonly held association of hyperthyroidism with sinus tachycardia and widened pulse pressure (PP) has not been reassessed in decades despite patients with hyperthyroidism in current practice not always present with these signs. The study objective was to assess prevalence and variability of sinus tachycardia and widened PP in present day among individuals with different degrees of hyperthyroidism.Methods: Data was collected retrospectively from 248 adult patients in an outpatient setting with biochemical evidence of hyperthyroidism, recorded heart rate (HR) and blood pressure (BP) who were not treated with medications that can influence these parameters.Results: Mean age was 42.0 ± 14.2 years with 66.9% being female. Median free thyroxine (fT4) level was 3.49 (IQR 2.42–4.58) ng/dL and thyroid stimulating hormone (TSH) 0.02 (IQR 0.01–0.03) mIU/L. Tachycardia, defined as HR >100 bpm, was present in 28.2%. In the lowest and highest fT4 quartiles, tachycardia was present in 16.4% and 38.7% respectively. Using logistic regression, tachycardia was associated with higher fT4 and diastolic BP. More lenient outcome of tachycardia with HR >90 bpm was seen in 47.2%. Widened PP, defined as >50 mmHg, was observed in 64.1% of patients and correlated with higher fT4 and BP.Conclusions: Tachycardia is not a common feature of hyperthyroidism today. The relatively infrequent finding of tachycardia in this study compared to older studies may reflect differences in the way medicine is practiced today. The increased ordering of thyroid function tests most likely unmasked cases of mild or asymptomatic thyrotoxicosis. A widened PP was a more prevalent clinical finding in this study.
- 2 September 2022
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 17 (9) , e0273724
Open AccessTachycardia in hyperthyroidism: Not so common
Objective: The commonly held association of hyperthyroidism with sinus tachycardia and widened pulse pressure (PP) has not been reassessed in decades despite patients with hyperthyroidism in current practice not always present with these signs. The study objective was to assess prevalence and variability of sinus tachycardia and widened PP in present day among individuals with different degrees of hyperthyroidism.Methods: Data was collected retrospectively from 248 adult patients in an outpatient setting with biochemical evidence of hyperthyroidism, recorded heart rate (HR) and blood pressure (BP) who were not treated with medications that can influence these parameters.Results: Mean age was 42.0 ± 14.2 years with 66.9% being female. Median free thyroxine (fT4) level was 3.49 (IQR 2.42–4.58) ng/dL and thyroid stimulating hormone (TSH) 0.02 (IQR 0.01–0.03) mIU/L. Tachycardia, defined as HR >100 bpm, was present in 28.2%. In the lowest and highest fT4 quartiles, tachycardia was present in 16.4% and 38.7% respectively. Using logistic regression, tachycardia was associated with higher fT4 and diastolic BP. More lenient outcome of tachycardia with HR >90 bpm was seen in 47.2%. Widened PP, defined as >50 mmHg, was observed in 64.1% of patients and correlated with higher fT4 and BP.Conclusions: Tachycardia is not a common feature of hyperthyroidism today. The relatively infrequent finding of tachycardia in this study compared to older studies may reflect differences in the way medicine is practiced today. The increased ordering of thyroid function tests most likely unmasked cases of mild or asymptomatic thyrotoxicosis. A widened PP was a more prevalent clinical finding in this study.
- 1 September 2020
- Published by Elsevier in Endocrine Practice
- Vol. 26 (9) , 953-959
Adrenal Vein Sampling Without Discontinuation of Mineralocorticoid Receptor Antagonist Therapy
- 1 September 2020
- Published by Elsevier in Endocrine Practice
- Vol. 26 (9) , 953-959
Adrenal Vein Sampling Without Discontinuation of Mineralocorticoid Receptor Antagonist Therapy
- 15 June 2020
- Published by Springer Nature in Journal of Racial and Ethnic Health Disparities
- Vol. 8 (2) , 332-338
Factors Associated with Diabetes Control in Predominately African American and Hispanic Population with Newly Diagnosed Type 2 Diabetes
Background This study characterizes factors affecting glycemic control in a predominately African American and Hispanic population with newly diagnosed type 2 diabetes (T2DM). Methods Retrospective longitudinal cohort study of 1638 patients with newly diagnosed T2DM to determine factors associated with improved HbA1c (ΔHbA1c ≤ − 0.5%) and achieving target HbA1c < 7%. Results At baseline, mean age 51.7 ± 11.5 years, males 52.9%, mean BMI 33.9 ± 7.8 kg/m2, median HbA1c 9.9 (7.6–12.1)%. At study end, median follow-up duration 27 (13–54) months, median HbA1c 7.0 (6.2–8.7)%, 69.6% with improved HbA1c, 48.3% achieved target HbA1c < 7%, 88.4% monitored blood glucose, 40.1% used insulin, and 72.4% reported not missing medications. In multivariate analysis, improved HbA1c significantly correlated with glucose monitoring (OR = 2.65), higher initial HbA1c (OR = 1.85), and medication adherence (OR = 1.66) and inversely correlated with insulin use (OR = 0.38) and follow-up duration (OR = 0.99). Achieving HbA1c < 7% significantly correlated with glucose monitoring (OR = 2.14), medication adherence (OR = 1.88), more provider visits (OR = 1.04), and older age (OR = 1.03). It inversely correlated with insulin use (OR = 0.47), initial HbA1c (OR = 0.93), and follow-up duration (OR = 0.98). Conclusions In those with newly diagnosed T2DM, achieving better glycemic control was mainly related to patient self-management behaviors and inversely related to insulin use. Emphasis on patients’ diabetes education and empowerment are critical to improved glycemic control.
- 15 June 2020
- Published by Springer Nature in Journal of Racial and Ethnic Health Disparities
- Vol. 8 (2) , 332-338
Factors Associated with Diabetes Control in Predominately African American and Hispanic Population with Newly Diagnosed Type 2 Diabetes
Background This study characterizes factors affecting glycemic control in a predominately African American and Hispanic population with newly diagnosed type 2 diabetes (T2DM). Methods Retrospective longitudinal cohort study of 1638 patients with newly diagnosed T2DM to determine factors associated with improved HbA1c (ΔHbA1c ≤ − 0.5%) and achieving target HbA1c < 7%. Results At baseline, mean age 51.7 ± 11.5 years, males 52.9%, mean BMI 33.9 ± 7.8 kg/m2, median HbA1c 9.9 (7.6–12.1)%. At study end, median follow-up duration 27 (13–54) months, median HbA1c 7.0 (6.2–8.7)%, 69.6% with improved HbA1c, 48.3% achieved target HbA1c < 7%, 88.4% monitored blood glucose, 40.1% used insulin, and 72.4% reported not missing medications. In multivariate analysis, improved HbA1c significantly correlated with glucose monitoring (OR = 2.65), higher initial HbA1c (OR = 1.85), and medication adherence (OR = 1.66) and inversely correlated with insulin use (OR = 0.38) and follow-up duration (OR = 0.99). Achieving HbA1c < 7% significantly correlated with glucose monitoring (OR = 2.14), medication adherence (OR = 1.88), more provider visits (OR = 1.04), and older age (OR = 1.03). It inversely correlated with insulin use (OR = 0.47), initial HbA1c (OR = 0.93), and follow-up duration (OR = 0.98). Conclusions In those with newly diagnosed T2DM, achieving better glycemic control was mainly related to patient self-management behaviors and inversely related to insulin use. Emphasis on patients’ diabetes education and empowerment are critical to improved glycemic control.
- 28 October 2019
- Published by The Endocrine Society in The Journal of Clinical Endocrinology & Metabolism
- Vol. 105 (3) , e906
Response to Letter to the Editor: “Hypernatremic Hydrophobic Transient Adipsia without Organic or Severe Psychiatric Disorder”
Aleida Rodriguez, Leon Fogelfeld, Gary Robertson; Response to Letter to the Editor: Hypernatremic Hydrophobic Transient Adipsia without Organic or Severe Psych
- 28 October 2019
- Published by The Endocrine Society in The Journal of Clinical Endocrinology & Metabolism
- Vol. 105 (3) , e906
Response to Letter to the Editor: “Hypernatremic Hydrophobic Transient Adipsia without Organic or Severe Psychiatric Disorder”
Aleida Rodriguez, Leon Fogelfeld, Gary Robertson; Response to Letter to the Editor: Hypernatremic Hydrophobic Transient Adipsia without Organic or Severe Psych
- 2 August 2019
- Published by The Endocrine Society in The Journal of Clinical Endocrinology & Metabolism
- Vol. 104 (11) , 5427-5430
Hypernatremic Hydrophobic Transient Adipsia Without Organic or Severe Psychiatric Disorder
Context: Psychogenic adipsic hypernatremia is an exceedingly rare and life-threatening condition, occurring in those with severe psychiatric disorders. Its diagnosis requires exclusion of congenital or acquired hypothalamic pathologic entities. We present the case of a patient who experienced transient severe hypernatremia without evidence of brain pathologic features or known psychiatric disease. In our patient, the transient adipsic hypernatremia had resulted from an episode of mild depression that resolved spontaneously. Case Description: A 46-year-old healthy woman who had had three recurrent admissions within 1 month had presented for evaluation of intractable nausea and vomiting with a history of a recent episode of a depressive mood change. Each admission had shown substantial hypernatremia (maximum plasma sodium, 166 mEq/L) accompanied by a strong aversion to consuming water. The findings from the diagnostic evaluation showed elevated serum osmolality and lower than expected urine osmolality (urine osmolality range, 474–501 mOsm/kg). This finding, along with an MRI scan showing the presence of a normal posterior pituitary bright spot, suggested that the osmoregulation of her thirst and arginine vasopressin (AVP) secretion were both defective during the attack. The patient was evaluated by psychiatry. Mild depression was diagnosed, and the patient started treatment with mirtazapine, which she only took for a few days. The patient’s hypernatremia had completely recovered with resolution of her depression within 2 months. Conclusion: A mild mood disorder can cause transient dysregulation of the thirst mechanism and AVP secretion through not yet identified mechanisms.
- 2 August 2019
- Published by The Endocrine Society in The Journal of Clinical Endocrinology & Metabolism
- Vol. 104 (11) , 5427-5430
Hypernatremic Hydrophobic Transient Adipsia Without Organic or Severe Psychiatric Disorder
Context: Psychogenic adipsic hypernatremia is an exceedingly rare and life-threatening condition, occurring in those with severe psychiatric disorders. Its diagnosis requires exclusion of congenital or acquired hypothalamic pathologic entities. We present the case of a patient who experienced transient severe hypernatremia without evidence of brain pathologic features or known psychiatric disease. In our patient, the transient adipsic hypernatremia had resulted from an episode of mild depression that resolved spontaneously. Case Description: A 46-year-old healthy woman who had had three recurrent admissions within 1 month had presented for evaluation of intractable nausea and vomiting with a history of a recent episode of a depressive mood change. Each admission had shown substantial hypernatremia (maximum plasma sodium, 166 mEq/L) accompanied by a strong aversion to consuming water. The findings from the diagnostic evaluation showed elevated serum osmolality and lower than expected urine osmolality (urine osmolality range, 474–501 mOsm/kg). This finding, along with an MRI scan showing the presence of a normal posterior pituitary bright spot, suggested that the osmoregulation of her thirst and arginine vasopressin (AVP) secretion were both defective during the attack. The patient was evaluated by psychiatry. Mild depression was diagnosed, and the patient started treatment with mirtazapine, which she only took for a few days. The patient’s hypernatremia had completely recovered with resolution of her depression within 2 months. Conclusion: A mild mood disorder can cause transient dysregulation of the thirst mechanism and AVP secretion through not yet identified mechanisms.
- Open Access
- 20 February 2019
- Published by Springer Nature in BMC Nephrology
- Vol. 20 (1) , 1-11
Insulin resistance and chronic kidney disease progression, cardiovascular events, and death: findings from the chronic renal insufficiency cohort study
Insulin resistance contributes to the metabolic syndrome, which is associated with the development of kidney disease. However, it is unclear if insulin resistance independently contributes to an increased risk of chronic kidney disease (CKD) progression or CKD complications. Additionally, predisposing factors responsible for insulin resistance in the absence of diabetes in CKD are not well described. This study aimed to describe factors associated with insulin resistance and characterize the relationship of insulin resistance to CKD progression, cardiovascular events and death among a cohort of non-diabetics with CKD. Data was utilized from Chronic Renal Insufficiency Cohort Study participants without diabetes (N = 1883). Linear regression was used to assess associations with insulin resistance, defined using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The relationship of HOMA-IR, fasting glucose, hemoglobin A1c (HbA1c), and C-peptide with CKD progression, cardiovascular events, and all-cause mortality was examined with Cox proportional hazards models. Novel positive associations with HOMA-IR included serum albumin, uric acid, and hemoglobin A1c. After adjustment, HOMA-IR was not associated with CKD progression, cardiovascular events, or all-cause mortality. There was a notable positive association of one standard deviation increase in HbA1c with the cardiovascular endpoint (HR 1.16, 95% CI: 1.00–1.34). We describe potential determinants of HOMA-IR among a cohort of non-diabetics with mild-moderate CKD. HOMA-IR was not associated with renal or cardiovascular events, or all-cause mortality, which adds to the growing literature describing an inconsistent relationship of insulin resistance with CKD-related outcomes.
- 20 February 2019
- Published by Springer Nature in BMC Nephrology
- Vol. 20 (1) , 1-11
Open AccessInsulin resistance and chronic kidney disease progression, cardiovascular events, and death: findings from the chronic renal insufficiency cohort study
Insulin resistance contributes to the metabolic syndrome, which is associated with the development of kidney disease. However, it is unclear if insulin resistance independently contributes to an increased risk of chronic kidney disease (CKD) progression or CKD complications. Additionally, predisposing factors responsible for insulin resistance in the absence of diabetes in CKD are not well described. This study aimed to describe factors associated with insulin resistance and characterize the relationship of insulin resistance to CKD progression, cardiovascular events and death among a cohort of non-diabetics with CKD. Data was utilized from Chronic Renal Insufficiency Cohort Study participants without diabetes (N = 1883). Linear regression was used to assess associations with insulin resistance, defined using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The relationship of HOMA-IR, fasting glucose, hemoglobin A1c (HbA1c), and C-peptide with CKD progression, cardiovascular events, and all-cause mortality was examined with Cox proportional hazards models. Novel positive associations with HOMA-IR included serum albumin, uric acid, and hemoglobin A1c. After adjustment, HOMA-IR was not associated with CKD progression, cardiovascular events, or all-cause mortality. There was a notable positive association of one standard deviation increase in HbA1c with the cardiovascular endpoint (HR 1.16, 95% CI: 1.00–1.34). We describe potential determinants of HOMA-IR among a cohort of non-diabetics with mild-moderate CKD. HOMA-IR was not associated with renal or cardiovascular events, or all-cause mortality, which adds to the growing literature describing an inconsistent relationship of insulin resistance with CKD-related outcomes.
- Open Access
- 1 November 2018
- Published by Elsevier in AACE Clinical Case Reports
- Vol. 4 (6) , e513-e517
Hypokalemia may Mask Primary Aldosteronism: A Case Series
- 1 November 2018
- Published by Elsevier in AACE Clinical Case Reports
- Vol. 4 (6) , e513-e517
Open AccessHypokalemia may Mask Primary Aldosteronism: A Case Series
- Open Access
- 11 October 2018
- Published by BMJ in BMJ Open Diabetes Research & Care
- Vol. 6 (1) , e000568
Newly diagnosed type 2 diabetes in an ethnic minority population: clinical presentation and comparison to other populations
Objective: To characterize the clinical presentation of newly diagnosed type 2 diabetes of ethnic minority adults in Chicago and compare with other populations. Research design and methods: Cross-sectional study examining the data of 2280 patients newly diagnosed with type 2 diabetes treated between 2003 and 2013 in a large Chicago public healthcare system. Results: Mean age of the patients was 49±11.3 years, men 54.4%, African-Americans 48.1%, Hispanics 32.5%, unemployed 69.9%, uninsured 82.2%, English-speaking 75.1%, and body mass index was 32.8±7.4 kg/m2. Microvascular complications were present in 50.1% and macrovascular complications in 13.4%. There was a presence of either macrovascular or microvascular complications correlated with older age, hypertension, dyslipidemia, inactivity, speaking English, and being insured (p1c (HbA1c) at presentation did not correlate with diabetes complications. In our cohort, when compared with a diverse population in the UK and insured population in the USA, HbA1c at presentation was 10.0% (86 mmol/mol), 6.6% (49 mmol/mol), and 8.2% (66 mmol/mol); nephropathy was 22.2%, 16.7%, and 5.7%; retinopathy was 10.7%, 7.9%, and 1.4%; and neuropathy was 27.7%, and 6.7% in the UK (p<0.001). There were no significant differences between groups in the prevalence of macrovascular complications. Conclusion: These results show the vulnerability of underserved and underinsured patients for developing diabetes complications possibly related to a delayed diagnosis.
- 11 October 2018
- Published by BMJ in BMJ Open Diabetes Research & Care
- Vol. 6 (1) , e000568
Open AccessNewly diagnosed type 2 diabetes in an ethnic minority population: clinical presentation and comparison to other populations
Objective: To characterize the clinical presentation of newly diagnosed type 2 diabetes of ethnic minority adults in Chicago and compare with other populations. Research design and methods: Cross-sectional study examining the data of 2280 patients newly diagnosed with type 2 diabetes treated between 2003 and 2013 in a large Chicago public healthcare system. Results: Mean age of the patients was 49±11.3 years, men 54.4%, African-Americans 48.1%, Hispanics 32.5%, unemployed 69.9%, uninsured 82.2%, English-speaking 75.1%, and body mass index was 32.8±7.4 kg/m2. Microvascular complications were present in 50.1% and macrovascular complications in 13.4%. There was a presence of either macrovascular or microvascular complications correlated with older age, hypertension, dyslipidemia, inactivity, speaking English, and being insured (p1c (HbA1c) at presentation did not correlate with diabetes complications. In our cohort, when compared with a diverse population in the UK and insured population in the USA, HbA1c at presentation was 10.0% (86 mmol/mol), 6.6% (49 mmol/mol), and 8.2% (66 mmol/mol); nephropathy was 22.2%, 16.7%, and 5.7%; retinopathy was 10.7%, 7.9%, and 1.4%; and neuropathy was 27.7%, and 6.7% in the UK (p<0.001). There were no significant differences between groups in the prevalence of macrovascular complications. Conclusion: These results show the vulnerability of underserved and underinsured patients for developing diabetes complications possibly related to a delayed diagnosis.
- 1 May 2018
- Published by Elsevier in Journal of Diabetes and its Complications
- Vol. 32 (5) , 474-479
Legacy effect in combined diabetic-renal multifactorial intervention in patients with advanced diabetic nephropathy
- 1 May 2018
- Published by Elsevier in Journal of Diabetes and its Complications
- Vol. 32 (5) , 474-479
Legacy effect in combined diabetic-renal multifactorial intervention in patients with advanced diabetic nephropathy
- 1 March 2017
- Published by Elsevier in Journal of Diabetes and its Complications
- Vol. 31 (3) , 624-630
Combined diabetes-renal multifactorial intervention in patients with advanced diabetic nephropathy: Proof-of-concept
- 1 March 2017
- Published by Elsevier in Journal of Diabetes and its Complications
- Vol. 31 (3) , 624-630
Combined diabetes-renal multifactorial intervention in patients with advanced diabetic nephropathy: Proof-of-concept