Effects of Whole Fruit on Glycemic Control, Liver Fat, and Cardiovascular Disease Risk Factors in Adults With Type 2 Diabetes
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 25
- 试验地点
- 1
- 主要终点
- Mean 24-hour Glucose Levels
研究概览
简要总结
This study will determine the effects of consuming whole fruit on blood sugar control, liver fat, and cardiovascular health in adults with type 2 diabetes who are not treated with insulin.
详细描述
Diabetes is one of the top three drivers of healthcare costs in the U.S., and nearly half of Americans will develop either diabetes or prediabetes in their lifetime. It is therefore critical to find new strategies to treat or reverse diabetes.
One such approach is adopting a healthy diet, which can dramatically improve blood sugar levels in adults with type 2 diabetes and even induce diabetes remission in some patients. Despite this, not much is known about which food groups are most effective at improving blood sugar levels in patients with diabetes.
Although individuals with type 2 diabetes are often advised to reduce carbohydrate intake, current dietary guidelines also recommend consuming fruit and other carbohydrate-rich foods. This has led to confusion among patients and clinicians about whether eating fruit, particularly in larger amounts, is beneficial or harmful for blood sugar and overall health. Whole fruit differs from many other carbohydrate sources in that whole fruit is rich in fiber, vitamins, minerals, and bioactive plant compounds, while being relatively low in energy density.
Most prior research examining the effects of whole fruit in people with type 2 diabetes has been epidemiologic, focused on individual fruits, or combined whole fruit with fruit juice and/or vegetables into a single food category. As a result, it is unknown how whole fruit, as a food category, affects glycemic control and cardiovascular health.
The investigators previously found that a whole-fruit-rich, Mediterranean-style diet improved blood sugar control and blood pressure in patients with type 2 diabetes and even allowed some patients to wean off all anti-hyperglycemic medications. The investigators will conduct a follow-up study to determine the effects of whole fruit alone on glycemic control, liver fat, and cardiovascular risk factors. The study will be a single-arm controlled feeding study to determine the effects of eating a large amount of whole fruit for 17 weeks on glycemic control (Aim 1), liver fat (Aim 2a), and cardiovascular disease risk factors (Aim 2b) in patients with insulin-independent type 2 diabetes. The primary measures of glycemic control will be mean 24-hour glucose levels (as measured by continuous glucose monitoring) and mean 3-hour glucose levels (as measured during a 3-hour oral glucose tolerance test). These assessments will be supplemented by, and interpreted in light of, other glycemic outcomes, which are listed as outcomes #3-9 below.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
盲法说明
Nurses and technicians who perform the assays and assessments will be blinded and will not be affiliated with the study. Data will be cleaned blinded by randomizing the order of the timepoints.
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Aged ≥18 years
- •Diagnosed with type 2 diabetes
- •HbA1c between 6.5-12.0%
- •Fasting C-peptide level ≥0.5 ng/ml, indicating the patient does not have beta-cell failure, as measured at screening
排除标准
- •On insulin
- •Evidence of latent autoimmune diabetes (LADA) or maturity-onset diabetes of the young (MODY)
- •Estimated glomerular filtration rate (eGFR) <45 ml/min per 1.73 m²
- •Heart attack in the past 6 months or severe/unstable heart failure
- •On weight loss medication, including GLP-1 receptor agonists (e.g., semaglutide, dulaglutide)
- •Change in the dosage of a chronic medication that may affect study endpoints within the past 3 months
- •Clinically significant laboratory abnormality (e.g., abnormal hemoglobin levels)
- •Significant gastrointestinal disease, major gastrointestinal surgery, or gallstones
- •Significant cardiovascular, renal, cardiac, liver, lung, adrenal, or nervous system disease that might compromise participant safety or data validity
- •Evidence of cancer (other than non-melanoma skin cancer) within the last 5 years
- •Lost or gained more than 5 lbs (or more than 2% of body weight if the patient weighs >250 lbs) of weight in the past 2 months
- •Pregnant, planning to become pregnant in the next 6 months, or breastfeeding
- •Major psychiatric condition that would affect the ability to participate in the study
- •Not able to eat the provided study meals (e.g., food allergies)
- •Behavioral factors or circumstances that may impede adherence to the dietary intervention
- •Not able to undergo the MRI scan (e.g., due to claustrophobia, implanted metal objects, or body girth ≥60 cm)
研究组 & 干预措施
Whole Fruit
Participants will consume a large amount of whole fruit, constituting 50% of total calories.
干预措施: Whole Fruit (Other)
结局指标
主要结局
Mean 24-hour Glucose Levels
时间窗: Change from baseline to week 17
Average 24-hour interstitial glucose levels (mg/dl), as measured by continuous glucose monitoring (CGM). If needed, data will be adjusted for any changes in antihyperglycemic medication use, using the medication effect score (MES).
Mean 3-hour Glucose Levels
时间窗: Change from baseline to week 17
Mean glucose (mg/dl) during a 3-hour oral glucose tolerance test (OGTT)
Mean 3-hour Insulin
时间窗: Change from baseline to week 17
Mean insulin (mU/l) during a 3-hour OGTT
Mean 3-hour C-Peptide
时间窗: Change from baseline to week 17
Mean C-Peptide (ng/ml) during a 3-hour OGTT
Insulin Sensitivity
时间窗: Change from baseline to week 17
Insulin sensitivity (dl/kg/min/μU/ml) during a 3-hour OGTT, as measured by the Oral C-Peptide Minimal Model
Dynamic Beta-Cell Responsivity
时间窗: Change from baseline to week 17
Phi\_dynamic during a 3-hour OGTT, as measured by the Oral C-Peptide Minimal Model (which is a set of 5 coupled differential equations; see reference under Citations). Phi\_dynamic is a measure of beta-cell responsiveness during first-phase insulin secretion. It is a dimensionless index (arbitrary units), where higher values denote greater insulin secretion
Static Beta-Cell Responsivity
时间窗: Change from baseline to week 17
Phi\_static during a 3-hour OGTT, as measured by the Oral C-Peptide Minimal Model (which is a set of 5 coupled differential equations; see reference under Citations). Phi\_static is a measure of beta-cell responsiveness during second-phase insulin secretion. The units of measure are min\^-1, and higher values denote greater insulin secretion.
Glycemic Variability
时间窗: Change from baseline to week 17
Measures of glucose variability derived from continuous glucose monitoring, including mean amplitude of glycemic excursions and standard deviation (mg/dl).
Time-in-range Metrics from CGM
时间窗: Change from baseline to week 17
Standard time-in-range metrics, including time-below-range (TBR), time-in-range (TIR), and time-above-range (TAR), as standardized by the International Consensus on Time in Range. Values will be reported as percentages of the 24-hour day.
次要结局
- Intrahepatic Lipid (Liver Fat)(Change from baseline to week 17)
- Body Weight(Change from baseline to week 17)
- Systolic and Diastolic Blood Pressure(Change from baseline to week 17)
- Heart Rate(Change from baseline to week 17)
- Lipids(Change from baseline to week 17)
研究者
Courtney Peterson
Associate Professor, Department of Nutrition
Harvard School of Public Health (HSPH)