Serum amylase and lipase activities in normal pregnancy: a prospective case-control study

OBJECTIVE

The diagnosis of acute pancreatitis during pregnancy is usually based on the association of upper abdominal pain, nausea or vomiting, and elevated serum amylase or lipase activities. The changes in these enzymatic activities have not been clearly established during normal pregnancy. The aim of this study was therefore to evaluate serum amylase and lipase activities in healthy pregnant women.

METHODS

Serum amylase and lipase activities were measured in 103 pregnant women (first trimester, n = 34; second trimester, n = 36; third trimester, n = 33) and in 103 nonpregnant women matched for age and not receiving oral contraception.

RESULTS

Serum amylase activity was similar in pregnant women and nonpregnant women during all trimesters of pregnancy. Serum lipase activity was significantly lower during the first trimester of pregnancy compared to nonpregnant women (48.6+/-27.6 vs 59.2+/-29.3 IU/L, p < 0.05) and compared to the third trimester (48.6+/-27.6 vs 76.3+/-35.8 IU/L, p < 0.001). Serum lipase activity was not statistically different between pregnant and nonpregnant women during the second and third trimesters.

CONCLUSION

An increase in serum amylase and lipase activities during pregnancy should be taken into account, as in nonpregnant women.

Liver function tests in normal pregnancy: a prospective study of 103 pregnant women and 103 matched controls

Except for increased serum alkaline phosphatase (AP) levels, the changes in liver function test (LFT) values during normal pregnancy have not been clearly established, mainly because most studies do not include matched controls. We therefore measured the serum values of routine liver tests including 5'-nucleotidase and total bile acids in 103 healthy pregnant women (first trimester, n = 34; second trimester, n = 36; third trimester, n = 33) and in 103 age-matched controls not receiving oral contraception. Fasting blood samples were taken. Because of hemodilution, serum albumin levels were significantly lower during all trimesters. As expected, AP activity was significantly higher in the third trimester. Serum aspartate transaminase (AST) activity and total bile acid (TBA) concentrations did not differ between pregnant and nonpregnant women. Serum alanine transaminase (ALT) activity was slightly higher in the second-trimester pregnant women than in controls (6.8 +/- 4.5 vs. 8.2 +/- 5.8, P = .04), although all values remained within normal limits. In pregnant women, total and free bilirubin concentrations were significantly lower during all three trimesters, as was conjugated bilirubin during the second and third trimesters. Serum gamma-glutamyl transpeptidase (GGT) activity was significantly lower in the second and third trimesters. Serum 5'-nucleotidase activity was slightly but significantly higher in the second and third trimesters. The knowledge of these results is useful for the interpretation of LFT values and the management of liver diseases during pregnancy.

Effects of fish oil on metabolic responses to oral fructose and glucose loads in healthy humans

This study examines the effect of the substitution of 6 g/day of fish oil in a saturated diet on glucose and fructose metabolism in healthy humans. Five subjects were submitted to two 3-wk controlled-diet periods (polyunsaturated/saturated = 0.21). During one period, 6 g/day of fat used for dressing were replaced by 6 g/day of fish oil [1.1 g/day of 20:5 (n-3) fatty acids and 0.7 g/day of 22:6 (n-3) fatty acids]. At the end of each period the subjects ingested a 1 g/kg fructose or glucose load 2 days apart. Plasma glucose fluxes were traced with the use of deuterated glucose and [U-13C]glucose. Substrate oxidation was measured by indirect calorimetry. Fish oil induced a 4% increase in basal and postload glycemia and a 40% decrease in insulinemia, whereas plasma C-peptide remained unaffected. Glucose fluxes were unaffected by fish oil, but carbohydrate (CHO) oxidation was reduced (fructose: 55.5 +/- 4.1 vs. 62.9 +/- 3.6 g/6 h; glucose: 36.7 +/- 4.7 vs. 50.5 +/- 4.7 g/6 h; all P < 0.05). Lipid oxidation was increased 35% by fish oil after both CHO loads. Nonoxidative glucose disposal was increased by fish oil (fructose: 9.4 +/- 2.5 vs. 2.9 +/- 1.1 g/6 h; glucose: 28.3 +/- 5.1 vs. 14.4 +/- 4.7 g/6 h; all P < 0.05). Fish oil could affect glucose transport and decrease CHO oxidation through the decrease in insulinemia and/or a specific effect on glycolytic pathway.

Protein-energy malnutrition in elderly medical patients

STUDY OBJECTIVE

To evaluate (1) the prevalence of protein-energy malnutrition in elderly patients; (2) the changes in nutritional status during the hospital stay; and (3) (main objective) the relationship between simple nutritional parameters and short-term in-hospital mortality.

DESIGN

Prospective time series at admission and on the 15th day of hospitalization.

SETTING

Medical care unit in a teaching hospital.

PARTICIPANTS

Consecutive sample of 324 hospitalized patients greater than or equal to 70 years (86.4% of eligible patients). Norms of measurements were obtained from a referred sample of healthy control subjects (26 males and 36 females).

MAIN OUTCOME MEASURES

Mid-arm circumference, triceps skinfold thickness, serum albumin, prealbumin, and retinol-binding protein levels were measured in patients at admission and on the 15th day.

RESULTS

(1) Prevalence of PEM was 30% in male and 41% in female patients. (2) Both mid-arm circumference and serum albumin level decreased over the first 15 days of hospital stay (53 patients, paired t test, P less than 0.05). Triceps skinfold thickness did not change. (3) A step-wise discriminant-function analysis determined the utility of the parameters at admission as predictors of in-hospital mortality before the 15th day. Mid-arm circumference, triceps skinfold thickness, albumin, and prealbumin levels, as well as age, are predictors of in-hospital mortality, with 73% sensitivity, 69% specificity, and 70% of correctly classified patients of both sexes.

CONCLUSIONS

Parameters used are predictors for short-term in-hospital mortality of elderly patients hospitalized in an acute medical unit. The lean body mass is preferentially mobilized for energy during hospitalization.

[Hypocaloric and high-protein diet in obese patients: changes in the lean mass]

We have followed for 40 days seven hospitalized, young (age, mean SD : 33 +/- 8 yrs), and moderately obese (W/H : 35 +/- 3.92) women. During the first 5 days (DO to D5) they received a diet similar to their customary home-diet; from D6 to D40, their daily caloric intake was adjusted to 3,41 +/- 0.13 MJ (816 +/- 30 kcal). This diet comprised 21 p. 100 of sugars, 35 p. 100 of lipids, 1.57 +/- 0.09 g proteins per kg ideal body weight. Five seven-day periods have been studied. On the first day of each period, we recorded body weight and measured plasma albumin, pre albumin, retinol binding protein, complement (CH50 and C3) C peptide (in the fasting state and after glucagon stimulation), and thyroid hormones (T3 and rT3). On each of the 35 days of this study, total nitrogen was measured (Kjeldahl's method) in food, urine and faeces. On D0 and D41 lean and fat body masses were evaluated through measurements of total water (dilution of tritiated water) and of skin fold thickness respectively. From D0 to D40, the average weight loss was 8.76 +/- 1.86 kg; the cumulated nitrogen balances were negative in 6 patients and positive in one, with variations from one period to another and from one patient to another. Plasma proteins and hormones did not vary significantly. Changes in lean mass were comprised between + 0,7 and -- 1,6 kg in spite of the fact that all patients received the same caloric and protein intake.