Effect of dietary fats and carbohydrate on blood pressure of mildly hypertensive patients.

The effect on blood pressure (BP) of replacing dietary saturated fat with either polyunsaturated fat (linoleic acid) or carbohydrate was studied in 21 untreated mildly hypertensive patients. In a randomized, double-blind, crossover protocol, all subjects received dietary supplements of cream, safflower oil, and carbohydrate in random sequence, each prepared in flavored yogurt or milk. Each supplement was administered for 6 weeks and followed by a 4-week washout period of no supplementation. Dietary linoleic acid increased from 4.6 to 13% of energy intake when the safflower oil replaced cream, while saturated fat decreased from 16 to 10%. Total fat intake was 37 to 38% during the cream and safflower oil periods but was 28% during the carbohydrate period. Compliance with the diets was demonstrated by significant changes in fasting plasma fatty acid measurements. Mean clinic BP was 135 +/- 9/93 +/- 6 mm Hg at baseline. There were no significant differences in BP measured in the clinic or at home among the three dietary periods. The protocol had more than 80% power to detect a mean effect of diet of 3 mm Hg systolic or 2 mm Hg diastolic BP. Therefore, replacing dietary saturated fat with carbohydrate or with linoleic acid does not affect BP in subjects with mild hypertension.

Effects of inherent responsiveness to diet and day-to-day diet variation on plasma lipoprotein concentrations.

We studied the biological variability and responsiveness to dietary fat of plasma lipoprotein cholesterol and triacylglycerol concentrations. Ten normal persons were studied on 3 consecutive days while they were eating their unrestricted usual diets and after 8, 9, and 10 d of eating a constant high-fat and low-fat diet administered in a crossover design. The changes in plasma low-density-lipoprotein (LDL)-cholesterol concentrations from baseline with the high-fat diet were inversely correlated with the changes from baseline with the low-fat diet (r = -0.74, P = 0.01), as well as with the changes from the low-fat to high-fat diet (r = -0.93, P < 0.001). The extent of increases in plasma LDL-cholesterol concentrations from the baseline to the high-fat diet were positively correlated with the increases from the low-fat to the high-fat diet (r = 0.93, P < 0.001). The responses of high-density-lipoprotein (HDL) cholesterol were not consistently correlated. The within-person between-day CV of LDL decreased from 10% with the unrestricted diet to 6% (P < 0.05) with the high-fat diet and to 7% with the low-fat diet (NS). The CV of total triacylglycerol (22%) and very-low-density-lipoprotein (VLDL) triacylglycerol (48%) on the unrestricted diet significantly decreased by 51-59% during both controlled diets (P = 0.03-0.06). The CV of HDL cholesterol was 5.3% during baseline, 4.2% during the high-fat diet, and 3.2% during the low-fat diet (P = 0.4, 0.19, respectively). In summary, individuals have a reproducible plasma LDL-cholesterol response when changing their dietary fat intake. The day-to-day variation in total triacylglycerol, VLDL triacylglycerol, and LDL-cholesterol concentrations decreases when day-to-day dietary variation is eliminated.

Biochemical investigations of cardiomyopathy in the dog.

Biochemical investigations were performed on cardiac muscle samples from seven dogs with cardiomyopathy and on cardiac muscle from a varied selection of normal dogs. Biochemical examination of cardiac muscle from clinical cases of cardiomyopathy revealed that the concentrations of three enzymes were significantly altered. These were, catalase, succinic dehydrogenase and malate dehydrogenase. Depressed enzyme concentrations were recorded from both ventricles but were significant only on the left for catalase, on the right for malate dehydrogenase and in both ventricles for succinic dehydrogenase although the depression in this case was also greater on the right.

Megaloesophagus and associated gastric heterotopia in the cat.

Two young adult male Siamese cats had heterotopic gastric mucosa in the dilated and inflamed oesophagi. Normally differentiated gastric mucosal glands were present and there was severe ulceration in one cat. It is uncertain whether the gastric heterotopia was a reparative change after oesophagitis or whether it represented a coincidental anatomical anomaly.