A controlled trial of a high fibre,low fat and low sodium diet for mild hypertension in type 2 (non-insulin-dependent) diabetic patients

Summary Fifty hypertensive Type 2 (non-insulin-dependent) diabetic patients were allocated, in a controlled trial, to a treatment diet of high fibre, low fat and low sodium composition, or to a control diet by the hospital dietitian. After 3 months treatment, the modified diet-treated group showed a highly significant reduction in mean systolic (180.5±19.0 to 165.0±20.7 mmHg) and diastolic blood pressure (96.6±9.3 to 88.0±10.5 mmHg), accompanied by significant reductions in urinary sodium excretion (183.0±62.1 to 121.7+ 65.8 mmol/day) glycosylated haemoglobin (12.4±3.1 to 10.5±2.9%), weight (74.6s±13.5 to 71.7±12.1 kg) and serum triglyceride levels (p<0.05). The mean values of diastolic pressure (p<0.01), urinary sodium/potassium ratio (p< 0.001), urinary potassium (p<0.01) was significantly reduced at 3 months compared to control. No changes in serum HDL-cholesterol levels were observed. The number of patients with normal blood pressure at 3 months was greater in the modified diet-treated group (ten versus five). Treatment of mild hypertension in diabetic subjects with this form of dietary regimen has a hypotensive response, with improvement in glycaemic control and no side effects. This modified diet may be an attractive alternative to anti-hypertensive drug therapy as a first line treatment.     

Randomised controlled trial of qigong in the treatment of mild essential hypertension

Exercise and relaxation decrease blood pressure. Qigong is a traditional Chinese exercise consisting of breathing and gentle movements. We conducted a randomised controlled trial to study the effect of Guolin qigong on blood pressure. In all, 88 patients with mild essential hypertension were recruited from the community and randomised to Goulin qigong or conventional exercise for 16 weeks. The main outcome measurements were blood pressure, health status (SF-36 scores), Beck Anxiety and Depression Inventory scores. In the qigong group, blood pressure decreased significantly from 146.3+/-7.8/93.0+/-4.1 mmHg at baseline to 135.5+/-10.0/87.1+/-7.7 mmHg at week 16. In the exercise group, blood pressure also decreased significantly from 140.9+/-10.9/93.1+/-3.5 mmHg to 129.7+/-11.1/86.0+/-7.0 mmHg. Heart rate, weight, BMI, waist circumference, total cholesterol, renin and 24 h urinary albumin excretion significantly decreased in both groups after 16 weeks. General health, bodily pain, social functioning and depression also improved in both groups. No significant differences between qigong and conventional exercise were found. In conclusion, Guolin qigong and conventional exercise have similar effects on blood pressure in patients with mild hypertension. While no additional benefits were identified, it is nevertheless an alternative to conventional exercise in the nondrug treatment of hypertension.     

Comparison of the hypotensive and metabolic effects of bendrofluazide therapy and a high fibre, low fat, low sodium diet in diabetic subjects with mild hypertension

Fifty diabetic patients with mild hypertension were treated by a high fibre, low fat and low sodium diet or bendrofluazide for a three-month period. These two well-matched groups had a similar highly significant decrease in both systolic (P less than 0.001) and diastolic blood pressure (P less than 0.001). Both groups lost weight, the weight loss being greater in those receiving dietary therapy. Only dietary therapy was associated with a significant elevation of HDL2 level (P less than 0.05) and decrease in glycosylated haemoglobin (P less than 0.01). Bendrofluazide therapy resulted in significant elevation of glycosylated haemoglobin level (P less than 0.05) and at the end of the study this group had significantly higher glycosylated haemoglobin level (P less than 0.05) than the diet treated group. In those patients who were also hyperlipidaemic, dietary therapy resulted in a significant decrease of mean serum cholesterol (P less than 0.02), triglyceride (P less than 0.01) and glycosylated haemoglobin (P less than 0.01) while bendrofluazide treatment tended to elevate these levels. We conclude that a high fibre, low fat and low sodium dietary regimen lowers blood pressure, improves several other coronary risk factors and appears free of side-effects. This modified diet may be an attractive alternative to thiazide diuretic therapy in the mildly hypertensive diabetic subject.     

A controlled trial of a low sodium, low fat, high fibre diet in treated hypertensive patients: effect on antihypertensive drug requirement in clinical practice.

The effect of a low sodium, low fat, high fibre diet in allowing a reduction of antihypertensive medication was compared with the effect produced by the individual components of this diet in an observer-blind controlled trial using 196 patients with essential hypertension. Patients were followed up 1.5 months after the last change in medication. In the control group a 33% reduction in medication was possible, with 24% of patients off medication altogether. The low fat, high fibre and low sodium groups showed larger reductions in medication (38%, 47% and 45% respectively), but not significant compared with the control group. The combination group had the largest and highly significant medication reduction (64%), and significantly more patients stopped medication (57.5%), compared with the control group. Since compliance assessment closely corresponded to normal clinical practice these results should represent what is possible in routine clinical practice. This is of importance as drug treatment has side effects, and may be associated with increased cardiovascular risk not found with dietary alternatives.     

Effect of a high carbohydrate, low sodium and low fat diet in type 2 diabetics with moderate hypertension

The effect of an intended diet, high in cereal fibre, low in fat and sodium was assessed over a 3-month period in 13 type 2 diabetic patients with moderate hypertension (diastolic blood pressure greater than 105 and less than 115 mmHg without antihypertension drug therapy). Eleven patients completed the study and two patients were withdrawn owing to an increase of blood pressure above initial values after 1 month. Using a compliance scoring system by an observer unaware of blood pressure response, patients were divided into those compliant to the dietary regimen (n = 7; group A) and those who were not, and therefore were considered controls (n = 4; group B). Group A demonstrated significant reductions in systolic (190.4 +/- 18 to 166.6 +/- 22.4 mmHg; P less than 0.02) and diastolic blood pressure (113.1 +/- 3.7 to 103.3 +/- 9.1 mmHg; P less than 0.01), weight (78.5 +/- 5.6 to 74.3 +/- 6.8 kg; P less than 0.02), daily urinary sodium excretion (210.3 +/- 79.9 to 120.3 +/- 56.1 mmol; P less than 0.02) and serum LDL levels (P less than 0.02). A reduction in glycosylated haemoglobin of 2.2 per cent was also noted. Three patients achieved a diastolic blood pressure level below 100 mmHg. In contrast, no significant changes occurred in group B. In particular, systolic and diastolic blood pressure (111.0 +/- 2.2 to 110.3 +/- 8.9 mmHg) remained unchanged. We conclude that the modified diet may have a hypotensive effect in diabetic subjects with moderate hypertension. However, the degree of blood pressure reduction suggests that this diet could, at best, only be considered an adjunct to conventional antihypertensive drug therapy.     

A dietary fibre supplement in the treatment of mild hypertension. A randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To study the effects of a dietary fibre supplement given as monotherapy upon blood pressure in mildly hypertensive patients. DESIGN: The investigation was performed as a prospective randomized, double-blind, placebo-controlled trial for 3 months. SETTING: Patients attending an outpatient hypertension clinic in a hospital. PATIENTS: Hypertensive patients with a minimum of two diastolic blood pressure (DBP) readings greater than 90 mmHg during a 2-week run-in period were included. Of the 65 patients enrolled, 63 were randomized (32 fibre, 31 placebo). Six patients did not complete the trial. INTERVENTION: Patients were treated with either fibre (7 g/day) or matching placebo. MAIN OUTCOME MEASURE: Based on previous studies, the a priori hypothesis was that dietary fibre supplementation could reduce blood pressure in hypertensive patients. RESULTS: Body weight was significantly reduced in the fibre group. Dietary fibre significantly reduced DBP and fasting serum insulin. However, no correlation between changes in body weight and systolic blood pressure or DBP was found. CONCLUSION: A dietary fibre supplement can lower DBP in mildly hypertensive patients independent of changes in body weight.     

Randomised, double blind, placebo controlled trial of inosine pranobex in rheumatoid arthritis.

In a randomised, placebo controlled, double blind study inosine pranobex was assessed as a possible second line drug in rheumatoid arthritis. Twenty four patients received inosine pranobex (3 g/day) and 26 patients received placebo for up to 24 weeks. Morning stiffness, articular index, grip strength, pain score, erythrocyte sedimentation rate, C reactive protein, IgG, IgM, and serum urate were assessed at weeks 0, 12, and 24. Baseline characteristics were similar except for a significantly higher C reactive protein in the placebo group. No significant improvement occurred in any variable: (a) when comparing week 0 with week 12 or week 24 for either group, (b) comparing active drug with placebo at week 12 or 24, or (c) taking all 50 patients as one group. Withdrawal from the study for lack of response or side effects was similar in both groups. Serum urate increased transiently but significantly with inosine pranobex (a recognised side effect). It is concluded that inosine pranobex has no second line activity in rheumatoid arthritis. Further, 50 patients effectively given placebo showed no spontaneous improvement in their disease activity.     

Controlled trial of low calcium versus high calcium intake in mild hypertension

A controlled trial of the effect of low versus high calcium intake on blood pressure was performed in 15 patients with mild essential hypertension (supine blood pressure after a 1-month run-in period: 145.7 +/- 2.6/97.8 +/- 0.9 mmHg, mean +/- s.e.m.). After a 1-week baseline period on a standard calcium intake (900 mg/day, obtained by giving a 500-mg calcium tablet daily, in addition to a 400-mg calcium diet), the patients were randomly entered into a double-blind crossover study of 4-week low calcium intake (400 mg calcium diet plus two placebo tablets/day) and 4-week high calcium intake (1400 mg/day: 400-mg calcium diet plus two 500-mg calcium tablets/day). Compliance with the diets appeared to be satisfactory, based on the results of food record analysis. No significant blood pressure change was observed at the end of the low-compared to the high-calcium regimen. Serum ionized calcium was slightly, but not significantly lower, while 24-h urinary calcium excretion was significantly reduced during the low-calcium diet. No difference was found in urinary sodium and potassium excretion between the two study periods. We conclude that moderate modifications of oral calcium intake are not associated with changes in blood pressure within the time span of this study.     

Long-term high fibre, low fat diet in gestational diabetes

A 30-year-old Caucasian who developed gestational diabetes in her first pregnancy requiring 58 U insulin daily and who subsequently adopted a high fibre, low fat diet and who was able to maintain normal glucose tolerance throughout a second pregnancy is reported.     

A controlled trial of a high dietary fibre intake in pregnancy — Effects on plasma glucose and insulin levels

Non-obese women in the second half of pregnancy were randomised into a control group receiving standard dietary advice and a group advised to make high fibre whole-food substitutions in their diets at every opportunity. Glucose and insulin profiles were performed over 24-h periods at 29 and 35 weeks gestation when the diets were equivalent in available carbohydrate, protein and fat, but the control group ingested 12.4 g dietary fibre/24 h and the high fibre group 51.4 g/24 h. Glucose homeostasis was similar in both groups but there was a significant attenuation of post-prandial insulin secretion in the high fibre group. It is suggested that the characteristic post-prandial peaks of plasma insulin observed in Western pregnant women are an unphysiological response to dietary fibre depletion.     

Impaired sodium excretion during mental stress in mild essential hypertension

In hypertensive rats, environmental stress causes sodium retention by an exaggerated increase in renal sympathetic nerve activity, which is modulated by angiotensin II. We tested whether similar effects can be observed in humans. In 66 normotensive subjects (half of them with a family history of hypertension) and 36 subjects with mild essential hypertension, urinary sodium excretion and renal hemodynamics were examined at rest and during mental stress treated either with placebo or ACE inhibition in a double-blind, randomized, cross-over design. Despite a marked increase in glomerular filtration rate in response to mental stress (Deltaglomerular filtration rate, 4.3+/-7.7 mL/min in normotensives without versus 5.6+/-8.4 mL/min in normotensives with a family history versus 10.1+/-5.7 mL/min in patients with mild essential hypertension; P:<0.002), the increase in urinary sodium excretion was blunted in patients with mild essential hypertension (Deltaurinary sodium excretion, 0.12+/-0.17 mmol/min versus 0.10+/-0.14 mmol/min versus 0.05+/-0.14 mmol/min; P:<0.05). ACE inhibition corrected the natriuretic response to mental stress in subjects with mild essential hypertension (Deltaurinary sodium excretion, 0.05+/-0.14 mmol/min with placebo versus 0.13+/-0.19 mmol/min with ACE inhibition; P:<0.01); thus, after ACE inhibition, urinary sodium excretion increased similarly in all 3 groups. In conclusion, impaired sodium excretion occurs during mental stress in human essential hypertension but not in subjects with positive family history of hypertension. This abnormality in sodium handling during activation of the sympathetic nervous system appears to be mediated by angiotensin II.     

Bevantolol vs propranolol: a double-blind controlled trial in essential hypertension

Bevantolol is a novel beta 1-selective beta-adrenoceptor antagonist. The Study Group evaluated its therapeutic utility (100-300 mg bid) compared with propranolol (80-240 mg bid) in 266 patients with mild to moderate essential hypertension (WHO Grades I and II, sitting diastolic blood pressure (DBP) greater than or equal to 95 mmHg). There was no difference in their antihypertensive efficacy over six months, 77% being controlled (DBP less than or equal to 90 mmHg) on bevantolol and 81% on propranolol. Hydrochlorothiazide 25-50 mg bid added later improved BP control in those incompletely controlled on bevantolol monotherapy. Both beta-adrenoceptor antagonists also reduced intraocular pressure. Bevantolol caused significantly fewer adverse effects than propranolol with many fewer withdrawals during long-term therapy. This unique clinical pharmacologic profile of bevantolol enhances its therapeutic usefulness and may relate to alpha-adrenoceptor antagonist activity, as well as to its beta 1-selectivity.     

Randomised controlled trial of use by hypercholesterolaemic patients of a vegetable oil sterol-enriched fat spread

Plant sterols may be a useful additive therapy in the treatment of hypercholesterolaemic patients. The purpose of this study was to determine the effect of a fat spread enriched with vegetable oil sterols on plasma lipid, lipoprotein and apolipoprotein concentrations. A randomised double blind placebo-controlled crossover trial with two consecutive periods of 8 weeks was conducted. 30 patients with heterozygous familial hypercholesterolaemia treated concurrently with an HMG-CoA reductase inhibitor (statin) and 32 patients with type IIa primary hypercholesterolaemia with a total cholesterol concentration >6.5 mmol/l not taking lipid-lowering drug therapy were recruited from a hospital lipid clinic. The active treatment was a fortified fat spread (25 g/day) providing 2.5 g of plant sterols. The control spread was indistinguishable in taste and appearance. Comparison at the end of the two 8-week trial periods showed a statistically significant reduction in total and LDL-cholesterol with use of the fortified spread but the results were confounded by a carry-over effect, which was partly explained by changes in the background diet. Because a carry-over effect was present, further analyses were restricted to the parallel arms of the first treatment period and were conducted on an intention to treat basis. After 4 weeks, LDL-cholesterol had decreased by 0.04 mmol/l ([0.8%] 95% confidence interval -0.44-0.37 NS) in the placebo group and decreased by -0.76 mmol/l ([15.0%] 95% CI -1.03--0.48, P<0.0001) in the active treatment group. After 8 weeks, the corresponding results were 0.0 mmol/l ([0.0%] 95% CI -0.26-0.24 NS) and -0.51 mmol/l ([10.0%] 95% CI -0.73--0.29 P<0.0001). There were no significant changes in apolipoprotein AI or B concentrations in the placebo group, but there was a small but statistically significant increase in apolipoprotein AI and a decrease in apolipoprotein B in the active treatment group. HDL cholesterol and triglyceride concentrations were unchanged. There was no difference in response between patients with statin-treated familial hypercholesterolaemia and patients with type IIa hyperlipoproteinaemia. We conclude that a fortified fat spread enriched with vegetable oil sterols reduces LDL-cholesterol by 10-15% with no difference in response between hypercholesterolaemic patients prescribed statins and those not taking lipid-lowering drug therapy.     

Treatment of mild hypertension. An attempted controlled therapeutic trial

A controlled trial of treatment of mild hypertension is described. Two hundred and thirty-three patients (149 females and 84 males) were included in the trial—all maintained diastolic blood pressure (BP) level between 90 and 110mmHg before entering the trial. All had symptomless, uncomplicated essential hypertension—the subjects were allocated to a treated or untreated control group, and the trial continued for 11 yr.Although the incidence of all complications of hypertension was less in the treated group for each sex, these differences were not significant, and the overall incidence of complications well below the number of patients in the control group who required treatment before completion of the trial, and scarcely greater than the number of patients who defaulted from the trial.The difficulties of successfully completing trials of this type are discussed and the need for larger, national trials of similar design, confirmed.     

Effect of dietary sodium chloride on gastro-oesophageal reflux: a randomized controlled trial

OBJECTIVE: It has been suggested that a high consumption of sodium chloride (NaCl) is associated with reflux symptoms. The objective of this study was to investigate the effect of increased dietary NaCl intake on gastro-oesophageal reflux and reflux mechanisms. MATERIAL AND METHODS: In this double-blind, placebo-controlled, crossover study 10 healthy male subjects received 5 g NaCl or placebo in capsules per day for one week, after which concurrent manometric, pH and impedance monitoring was carried out for 4.5 h. RESULTS: Oesophageal acid exposure time (pH < 4) was similar for placebo (median 11% (25th 3-75th 36)) and NaCl (9% (1-36)). No differences in the numbers of reflux episodes were found for NaCl (16 (13.5-22)) and placebo (23 (14.8-27)). Furthermore, similar numbers of liquid acid reflux episodes (placebo 12 (6.5-17.3); NaCl 10 (2.3-14.3)), liquid weakly acidic reflux episodes (placebo 5.5 (4-12.3); NaCl 6.5 (3-10.8)) and gaseous reflux episodes (placebo 1 (0-1.8); NaCl 2 (0-3)) were seen. In both conditions transient lower oesophageal sphincter relaxations (TLOSRs) were the most common reflux mechanism, followed by swallow-induced reflux. High salt intake lowered LOS pressure overall and in the first postprandial hour (p<0.01). CONCLUSIONS: High dietary sodium intake does not increase gastro-oesophageal reflux in healthy volunteers, despite a decrease in LOS pressure.