Background and Objectives:Very-low calorie diets(VLCD)achieve weight loss and remission of Type 2 diabetes(T2DM),but efficacy and acceptability in non-European populations is less clear.This feasibility study examines...Background and Objectives:Very-low calorie diets(VLCD)achieve weight loss and remission of Type 2 diabetes(T2DM),but efficacy and acceptability in non-European populations is less clear.This feasibility study examines the impact of 10%weight loss through VLCD on metabolic and body composition outcomes in a multiethnic cohort of Aotearoa New Zealand(AoNZ)men with prediabetes/early T2DM,and VLCD tolerability/cultural acceptability.Methods and Study Design:Participants followed a VLCD intervention(mean energy 3033kJ/day)until achievement of 10%weight loss.An oral glucose tolerance test(OGTT),hyperinsulinaemic isoglycaemic clamp with stable isotopes,hood calorimetry and dual-energy Xray absorptiometry(DXA)were undertaken before and after intervention.Qualitative data on VLCD tolerability/cultural acceptability were collected.Results:Fifteen participants were enrolled;nine achieved 10%weight loss.In this group,mean HbA1c reduced by 4.8mmol/mol(2.4-7.1)and reverted to normoglycaemia in n=5/9;mean body weight reduced by 12.0 kg(11.0-13.1)and whole-body glucose disposal improved by 1.5 mg kgFFM^(-1)min^(-1)(0.7-2.2).Blood pressure and fasting triglycerides improved significantly.No changes in hepatic glucose metabolism were found.In all participants who attended completion testing,HbA1c reduced by 3.4mmol/mol(SD 3.5)and total weight by 9.0kg(SD 5.7).The intervention was highly tolerable/culturally acceptable however challenges with fulfilment of cultural obligations were described.Conclusions:Results support VLCD use in AoNZ however further work to investigate ethnic differences in physiological response to VLCDs and to optimise protocols for multi-ethnic populations are required.展开更多
A new fully digital and home-built NMR (Nuclear Magnetic Resonance) spectrometer working at very-low magnetic field (4.5 mT) is presented. This spectrometer was initially dedicated for the in situ measurement of the a...A new fully digital and home-built NMR (Nuclear Magnetic Resonance) spectrometer working at very-low magnetic field (4.5 mT) is presented. This spectrometer was initially dedicated for the in situ measurement of the absolute polarization of hyperpolarized 129Xe. It allows detection and acquisition of NMR signals of proton (1H) at 190 kHz and of hyperpolarized xenon-129 (HP 129Xe) at 50 kHz. In this new NMR instrument, we replaced as much analog electronics as possible by digital electronic and software. Except for the power amplifier and the preamplifier, the whole system is digital. The transmitter is based on the use of a Direct Digital Synthesizer (DDS) board. The receiving board allows direct digitalization of the NMR signals thanks to an 8-bits analog-to-digital converter (ADC) clocked at 100 MHz. Decimation is preformed to dramatically improve the ADC resolution so as the final achieved effective resolution could be as high as 14-bits at 5 MHz sampling frequency. NMR signals are then digitally downconverted (DDC). Low-pass decimation filtering is applied on the base-band signals (I/Q) to enhance much more the dynamic range. The system requires little hardware. The transmitter and the receiver are controlled using Labview environment. It is a versatile, flexible and easy-to-replicate system. This was actually one of underlying ideas behind this development. Both 1H and hyperpolarized 129Xe NMR signals were successfully acquired. The system is used for the measurement of the absolute polarization of hyperpolarized 129Xe in hyperpolarizing experiments for the brain perfusion measurements. The high degree of flexibility of this new design allows its use for a large palette of other potential applications.展开更多
基金Health Research Council of New Zealand(HRC 17/542)the New Zealand Society for the Study of Diabetes(2016 NZSSD NZMS Medical Technology Grant)+1 种基金the University of Otago(University of Otago Research Grant 2017)for their study fundingthe Health Research Council of New Zealand for Clinical Research Training Fellowship funding(HRC 16/058)for PW.
文摘Background and Objectives:Very-low calorie diets(VLCD)achieve weight loss and remission of Type 2 diabetes(T2DM),but efficacy and acceptability in non-European populations is less clear.This feasibility study examines the impact of 10%weight loss through VLCD on metabolic and body composition outcomes in a multiethnic cohort of Aotearoa New Zealand(AoNZ)men with prediabetes/early T2DM,and VLCD tolerability/cultural acceptability.Methods and Study Design:Participants followed a VLCD intervention(mean energy 3033kJ/day)until achievement of 10%weight loss.An oral glucose tolerance test(OGTT),hyperinsulinaemic isoglycaemic clamp with stable isotopes,hood calorimetry and dual-energy Xray absorptiometry(DXA)were undertaken before and after intervention.Qualitative data on VLCD tolerability/cultural acceptability were collected.Results:Fifteen participants were enrolled;nine achieved 10%weight loss.In this group,mean HbA1c reduced by 4.8mmol/mol(2.4-7.1)and reverted to normoglycaemia in n=5/9;mean body weight reduced by 12.0 kg(11.0-13.1)and whole-body glucose disposal improved by 1.5 mg kgFFM^(-1)min^(-1)(0.7-2.2).Blood pressure and fasting triglycerides improved significantly.No changes in hepatic glucose metabolism were found.In all participants who attended completion testing,HbA1c reduced by 3.4mmol/mol(SD 3.5)and total weight by 9.0kg(SD 5.7).The intervention was highly tolerable/culturally acceptable however challenges with fulfilment of cultural obligations were described.Conclusions:Results support VLCD use in AoNZ however further work to investigate ethnic differences in physiological response to VLCDs and to optimise protocols for multi-ethnic populations are required.
文摘A new fully digital and home-built NMR (Nuclear Magnetic Resonance) spectrometer working at very-low magnetic field (4.5 mT) is presented. This spectrometer was initially dedicated for the in situ measurement of the absolute polarization of hyperpolarized 129Xe. It allows detection and acquisition of NMR signals of proton (1H) at 190 kHz and of hyperpolarized xenon-129 (HP 129Xe) at 50 kHz. In this new NMR instrument, we replaced as much analog electronics as possible by digital electronic and software. Except for the power amplifier and the preamplifier, the whole system is digital. The transmitter is based on the use of a Direct Digital Synthesizer (DDS) board. The receiving board allows direct digitalization of the NMR signals thanks to an 8-bits analog-to-digital converter (ADC) clocked at 100 MHz. Decimation is preformed to dramatically improve the ADC resolution so as the final achieved effective resolution could be as high as 14-bits at 5 MHz sampling frequency. NMR signals are then digitally downconverted (DDC). Low-pass decimation filtering is applied on the base-band signals (I/Q) to enhance much more the dynamic range. The system requires little hardware. The transmitter and the receiver are controlled using Labview environment. It is a versatile, flexible and easy-to-replicate system. This was actually one of underlying ideas behind this development. Both 1H and hyperpolarized 129Xe NMR signals were successfully acquired. The system is used for the measurement of the absolute polarization of hyperpolarized 129Xe in hyperpolarizing experiments for the brain perfusion measurements. The high degree of flexibility of this new design allows its use for a large palette of other potential applications.
