Amy McKenzie

Dr. Amy McKenzie

Virta Health
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 February 2018 in Diabetes Therapy
Verified
Journal Article
Open access
PDF file
SHSarah J. Hallberg
Sarah J. Hallberg
Amy McKenzieAmy McKenzie
Amy McKenzie
PWPaul T. Williams
Paul T. Williams
NBNasir H. Bhanpuri
Nasir H. Bhanpuri
APAnne L. Peters
Anne L. Peters
JVJeff S. Volek
Jeff S. Volek
Introduction Carbohydrate restriction markedly improves glycemic control in patients with type 2 diabetes (T2D) but necessitates prompt medication changes. Therefore, we assessed the effectiveness and safety of a novel care model providing continuous remote care with medication management based on biometric feedback combined with the metabolic approach of nutritional ketosis for T2D management. Methods We conducted an open-label, non-randomized, controlled, before-and-after 1-year study of this continuous care intervention (CCI) and usual care (UC). Primary outcomes were glycosylated hemoglobin (HbA1c), weight, and medication use. Secondary outcomes included fasting serum glucose and insulin, HOMA-IR, blood lipids and lipoproteins, liver and kidney function markers, and high-sensitivity C-reactive protein (hsCRP). Results 349 adults with T2D enrolled: CCI: n = 262 [mean (SD); 54 (8) years, 116.5 (25.9) kg, 40.4 (8.8) kg m2, 92% obese, 88% prescribed T2D medication]; UC: n = 87 (52 (10) years, 105.6 (22.15) kg, 36.72 (7.26) kg m2, 82% obese, 87% prescribed T2D medication]. 218 participants (83%) remained enrolled in the CCI at 1 year. Intention-to-treat analysis of the CCI (mean ± SE) revealed HbA1c declined from 59.6 ± 1.0 to 45.2 ± 0.8 mmol mol−1 (7.6 ± 0.09% to 6.3 ± 0.07%, P < 1.0 × 10−16), weight declined 13.8 ± 0.71 kg (P < 1.0 × 10−16), and T2D medication prescription other than metformin declined from 56.9 ± 3.1% to 29.7 ± 3.0% (P < 1.0 × 10−16). Insulin therapy was reduced or eliminated in 94% of users; sulfonylureas were entirely eliminated in the CCI. No adverse events were attributed to the CCI. Additional CCI 1-year effects were HOMA-IR − 55% (P = 3.2 × 10−5), hsCRP − 39% (P < 1.0 × 10−16), triglycerides − 24% (P < 1.0 × 10−16), HDL-cholesterol + 18% (P < 1.0 × 10−16), and LDL-cholesterol + 10% (P = 5.1 × 10−5); serum creatinine and liver enzymes (ALT, AST, and ALP) declined (P ≤ 0.0001), and apolipoprotein B was unchanged (P = 0.37). UC participants had no significant changes in biomarkers or T2D medication prescription at 1 year. Conclusions These results demonstrate that a novel metabolic and continuous remote care model can support adults with T2D to safely improve HbA1c, weight, and other biomarkers while reducing diabetes medication use. ClinicalTrials.gov Identifier NCT02519309. Funding Virta Health Corp.

13 August 2019 in European Journal of Preventive Cardiology
Verified
Journal Article
Open access
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KLKatharina Lechner
Katharina Lechner
CSClemens von Schacky
Clemens von Schacky
Amy McKenzieAmy McKenzie
Amy McKenzie
NWNicolai Worm
Nicolai Worm
UNUwe Nixdorff
Uwe Nixdorff
JSJohannes Scherr
Johannes Scherr
Despite major efforts to reduce atherosclerotic cardiovascular disease (ASCVD) burden with conventional risk factor control, significant residual risk remains. Recent evidence on non-traditional determinants of cardiometabolic health has advanced our understanding of lifestyle–disease interactions. Chronic exposure to environmental stressors like poor diet quality, sedentarism, ambient air pollution and noise, sleep deprivation and psychosocial stress affect numerous traditional and non-traditional intermediary pathways related to ASCVD. These include body composition, cardiorespiratory fitness, muscle strength and functionality and the intestinal microbiome, which are increasingly recognized as major determinants of cardiovascular health. Evidence points to partially overlapping mechanisms, including effects on inflammatory and nutrient sensing pathways, endocrine signalling, autonomic function and autophagy. Of particular relevance is the potential of low-risk lifestyle factors to impact on plaque vulnerability through altered adipose tissue and skeletal muscle phenotype and secretome. Collectively, low-risk lifestyle factors cause a set of phenotypic adaptations shifting tissue cross-talk from a proinflammatory milieu conducive for high-risk atherosclerosis to an anti-atherogenic milieu. The ketone body ß-hydroxybutyrate, through inhibition of the NLRP-3 inflammasome, is likely to be an intermediary for many of these observed benefits. Adhering to low-risk lifestyle factors adds to the prognostic value of optimal risk factor management, and benefit occurs even when the impact on conventional risk markers is discouragingly minimal or not present. The aims of this review are (a) to discuss novel lifestyle risk factors and their underlying biochemical principles and (b) to provide new perspectives on potentially more feasible recommendations to improve long-term adherence to low-risk lifestyle factors.

5 June 2019 in Frontiers in Endocrinology
Verified
Journal Article
Open access
PDF file
SAShaminie J. Athinarayanan
Shaminie J. Athinarayanan
RARebecca N. Adams
Rebecca N. Adams
SHSarah J. Hallberg
Sarah J. Hallberg
Amy McKenzieAmy McKenzie
Amy McKenzie
NBNasir H. Bhanpuri
Nasir H. Bhanpuri
JMJames McCarter
James McCarter
Purpose: Studies on long-term sustainability of low-carbohydrate approaches to treat diabetes are limited. We previously reported the effectiveness of a novel digitally-monitored continuous care intervention (CCI) including nutritional ketosis in improving weight, glycemic outcomes, lipid, and liver marker changes at 1 year. Here, we assess the effects of the CCI at 2 years. Materials and methods: An open label, non-randomized, controlled study with 262 and 87 participants with T2D were enrolled in the CCI and usual care (UC) groups, respectively. Primary outcomes were retention, glycemic control, and weight changes at 2 years. Secondary outcomes included changes in body composition, liver, cardiovascular, kidney, thyroid and inflammatory markers, diabetes medication use and disease status. Results: Reductions from baseline to 2 years in the CCI group resulting from intent-to-treat analyses included: HbA1c, fasting glucose, fasting insulin, weight, systolic blood pressure, diastolic blood pressure, triglycerides, and liver alanine transaminase, and HDL-C increased. Spine bone mineral density in the CCI group was unchanged. Use of any glycemic control medication (excluding metformin) among CCI participants declined (from 55.7 to 26.8%) including insulin (-62%) and sulfonylureas (-100%). The UC group had no changes in these parameters (except uric acid and anion gap) or diabetes medication use. There was also resolution of diabetes (reversal, 53.5%; remission, 17.6%) in the CCI group but not in UC. All the reported improvements had p < 0.00012. Conclusion: The CCI group sustained long-term beneficial effects on multiple clinical markers of diabetes and cardiometabolic health at 2 years while utilizing less medication. The intervention was also effective in the resolution of diabetes and visceral obesity with no adverse effect on bone health. Clinical Trial Registration: Clinicaltrials.gov NCT02519309

1 May 2018 in Cardiovascular Diabetology
Verified
Journal Article
Open access
PDF file
NBNasir H. Bhanpuri
Nasir H. Bhanpuri
SHSarah J. Hallberg
Sarah J. Hallberg
PWPaul T. Williams
Paul T. Williams
Amy McKenzieAmy McKenzie
Amy McKenzie
KBKevin D. Ballard
Kevin D. Ballard
JVJeff S. Volek
Jeff S. Volek
Background: Cardiovascular disease (CVD) is a leading cause of death among adults with type 2 diabetes mellitus (T2D). We recently reported that glycemic control in patients with T2D can be significantly improved through a continuous care intervention (CCI) including nutritional ketosis. The purpose of this study was to examine CVD risk factors in this cohort.Methods: We investigated CVD risk factors in patients with T2D who participated in a 1 year open label, non-randomized, controlled study. The CCI group (n = 262) received treatment from a health coach and medical provider. A usual care (UC) group (n = 87) was independently recruited to track customary T2D progression. Circulating biomarkers of cholesterol metabolism and inflammation, blood pressure (BP), carotid intima media thickness (cIMT), multi-factorial risk scores and medication use were examined. A significance level of P < 0.0019 ensured two-tailed significance at the 5% level when Bonferroni adjusted for multiple comparisons.Results: The CCI group consisted of 262 participants (baseline mean (SD): age 54 (8) year, BMI 40.4 (8.8) kg m−2). Intention-to-treat analysis (% change) revealed the following at 1-year: total LDL-particles (LDL-P) (− 4.9%, P = 0.02), small LDL-P (− 20.8%, P = 1.2 × 10−12), LDL-P size (+ 1.1%, P = 6.0 × 10−10), ApoB (− 1.6%, P = 0.37), ApoA1 (+ 9.8%, P < 10−16), ApoB/ApoA1 ratio (− 9.5%, P = 1.9 × 10−7), triglyceride/HDL-C ratio (− 29.1%, P < 10−16), large VLDL-P (− 38.9%, P = 4.2 × 10−15), and LDL-C (+ 9.9%, P = 4.9 × 10−5). Additional effects were reductions in blood pressure, high sensitivity C-reactive protein, and white blood cell count (all P < 1 × 10−7) while cIMT was unchanged. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk score decreased − 11.9% (P = 4.9 × 10−5). Antihypertensive medication use was discontinued in 11.4% of CCI participants (P = 5.3 × 10−5). The UC group of 87 participants [baseline mean (SD): age 52 (10) year, BMI 36.7 (7.2) kg m−2] showed no significant changes. After adjusting for baseline differences when comparing CCI and UC groups, significant improvements for the CCI group included small LDL-P, ApoA1, triglyceride/HDL-C ratio, HDL-C, hsCRP, and LP-IR score in addition to other biomarkers that were previously reported. The CCI group showed a greater rise in LDL-C.Conclusions: A continuous care treatment including nutritional ketosis in patients with T2D improved most biomarkers of CVD risk after 1 year. The increase in LDL-cholesterol appeared limited to the large LDL subfraction. LDL particle size increased, total LDL-P and ApoB were unchanged, and inflammation and blood pressure decreased.Trial registrationClinicaltrials.gov: NCT02519309. Registered 10 August 2015

7 March 2017 in JMIR Diabetes
Verified
Journal Article
Open access
Amy McKenzieAmy McKenzie
Amy McKenzie
SHSarah Hallberg
Sarah Hallberg
BCBrent C Creighton
Brent C Creighton
BVBrittanie M Volk
Brittanie M Volk
TLTheresa M Link
Theresa M Link
SPStephen Phinney
Stephen Phinney
Emerging Technologies, Medical Devices, Apps, Sensors, and Informatics to Help People with Diabetes

28 April 2020 in Metabolic Syndrome and Related Disorders
Verified
Journal Article
Open access
KLKatharina Lechner
Katharina Lechner
Amy McKenzieAmy McKenzie
Amy McKenzie
NKNicolle Kränkel
Nicolle Kränkel
CSClemens Von Schacky
Clemens Von Schacky
NWNicolai Worm
Nicolai Worm
RKRonald M. Krauss
Ronald M. Krauss
Current algorithms for assessing risk of atherosclerotic cardiovascular disease (ASCVD) and, in particular, the reliance on low-density lipoprotein (LDL) cholesterol in conditions where this measurement is discordant with apoB and LDL-particle concentrations fail to identify a sizeable part of the population at high risk for adverse cardiovascular events. This results in missed opportunities for ASCVD prevention, most notably in those with metabolic syndrome, prediabetes, and diabetes. There is substantial evidence that accumulation of ectopic fat and associated metabolic traits are markers for and pathogenic components of high-risk atherosclerosis. Conceptually, the subset of advanced lesions in high-risk atherosclerosis that triggers vascular complications is closely related to a set of coordinated high-risk traits clustering around a distinct metabolic phenotype. A key feature of this phenotype is accumulation of ectopic fat, which, coupled with age-related muscle loss, creates a milieu conducive for the development of ASCVD: atherogenic dyslipidemia, nonresolving inflammation, endothelial dysfunction, hyperinsulinemia, and impaired fibrinolysis. Sustained vascular inflammation, a hallmark of high-risk atherosclerosis, impairs plaque stabilization in this phenotype. This review describes how metabolic and inflammatory processes that are promoted in large measure by ectopic adiposity, as opposed to subcutaneous adipose tissue, relate to the pathogenesis of high-risk atherosclerosis. Clinical biomarkers indicative of these processes provide incremental information to standard risk factor algorithms and advanced lipid testing identifies atherogenic lipoprotein patterns that are below the discrimination level of standard lipid testing. This has the potential to enable improved identification of high-risk patients who are candidates for therapeutic interventions aimed at prevention of ASCVD.