Effects of therapeutic lifestyle change diets on blood lipids, lipoproteins, glycemic parameters, and blood pressure: a systematic review and meta-analysis of clinical trials

CONTEXT

Cardiovascular disease is the leading cause of death worldwide. Low-calorie, low-fat therapeutic diets (TDs) developed by the US National Cholesterol Education Program, ie, the Step I and II diets and the therapeutic lifestyle changes diet, are approximately similar and are the initial therapeutic interventional approaches for lifestyle modification.

OBJECTIVE

This systematic review with meta-analysis was undertaken to evaluate the effects of TDs diet on blood lipids, apolipoprotein A-1, apolipoprotein B, blood pressure, fasting blood glucose, and insulin.

DATA SOURCES

A comprehensive search of the PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar databases until October 2022 was performed to identify clinical trials investigating the effects of TDs on the aforementioned parameters.

DATA EXTRACTION

One investigator screened the records and extracted data, and another reviewed the extracted data.

DATA ANALYSIS

A total of 910 records were retrieved. After records were screened for eligibility, 34 clinical trials met the inclusion criteria. The pooled analysis from the random-effects model revealed a significant reduction in total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-1, and apolipoprotein B in the TD intervention group vs the control group. The overall effects of TDs on fasting blood glucose, insulin, and blood pressure were not significant, but the results of subgroup analysis revealed a significant reduction in fasting blood glucose with the Step II diet and an intervention duration of more than 24 weeks. For blood pressure, the Step I diet and an intervention duration of more than 24 weeks resulted in significant reduction. There was no evidence of publication bias, but strong heterogeneity was observed.

CONCLUSION

Therapeutic diets have promising effects on lipid profile parameters, glycemic indexes, and blood pressure, which can promote cardiovascular health.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021259355.

Lipid-Lowering Effects of Fluvastatin in Renal Transplant Patients. A Clinical Observation

A Atherosclerosis-related cardiovascular disease remains an important cause of morbidity and mortality in renal transplant patients. We assessed the efficacy and safety of the newer synthetic HMG-CoA reductase inhibitor, fluvastatin, in 12 renal transplant patients who remained hypercholesterolemic, despite having been on the American Heart Association (AHA) Step I diet for 6 weeks. At 8 weeks, compared to the control phase, fluvastatin therapy, 20 mg/day, reduced the total cholesterol (TC) from 321 ± 57 [± SD] to 301 ± 123 mg/dl (p=0.3); low-density lipoprotein cholesterol (LDL-C), from 209 ± 56 to 176 ± 81 mg/dl (p=0.2); and the triglyceride (TG) levels from 343 ± 119 to 277 ± 117 mg/dl (p=0.06); all these changes were statistically insignificant. However, the therapy significantly increased the high-density lipoprotein cholesterol (HDL-C) from 37 ± 11 to 46 ± 13 mg/dl (p=0.006). During this short-term treatment period no adverse biochemical effects were noted with the therapy.

Can low-fat/cholesterol nutrition counseling improve food intake habits and hyperlipidemia of renal transplant patients?

OBJECTIVE

To assess the impact of low-fat/cholesterol nutrition counseling on food intake habits and blood lipid levels of renal transplant patients.

DESIGN

Prospective practice-based outcome study.

SETTING

Acute care hospital post-renal transplant outpatient clinic.

PATIENTS

Forty-three renal transplant patients not on lipid-lowering medications referred to the renal dietitian for low-fat/cholesterol nutrition counseling between September 1994 and September 1997.

INTERVENTION

Individual assessment and counseling using the Healthy Heart Nutrition Guidelines Step 1 diet (<30% of total calories from fat, <300 mg cholesterol, and <10% of total calories from saturated fatty acids).

MAIN OUTCOME MEASURES

Three-day food records precounseling and 3-day food records (n = 13) or descriptive intake changes (n = 30) postcounseling (time interval: 2 to 8 months). Fasting/random serum total cholesterol, high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C), as available.

RESULTS

Total cholesterol (n = 43) and LDL-C (n = 22) decreased significantly (0. 54 mmol/L P <.000 and 0.53 mmol/L P <.000, respectively). There were no significant changes in HDL-C and triglycerides. Twenty percent of patients (n = 43) reached target levels of total cholesterol <5.2 mmol/L, and 35% of patients (n = 22) reached target levels of LDL-C <3.4 mmol/L. Percentage of total calories from fat decreased significantly (7.58% P <.03). Descriptive intake changes of lower fat choices were reported in the no post-food records group.

CONCLUSION

Patients can make changes in food intake habits after nutrition counseling. Serum lipid levels can improve after nutrition counseling, but many patients may still require lipid lowering medications to reach target levels. Nutrition counseling should be considered for the initial treatment of hyperlipidemia in renal transplant patients.