Biomedical subjects

X R Xi

Publications and source records attributed to X R Xi.

16 recordsLinked to original sources

PubMed2000

The ocular hypotensive effect of late pregnancy is higher in multigravidae than in primigravidae.

BACKGROUND: Systemic hypertension and degenerative vascular disease are more common in multigravidae than in primigravidae. The present study investigated whether the known ocular hypotensive effect of late pregnancy is influenced by the number of pregnancies. METHODS: Intraocular pressure (IOP) was measured in normotensive third-trimester primigravidae and multigravidae along with nulligravida controls by means of the Goldmann applanation tonometer. Depending upon the number of previous pregnancies, multigravidae were divided into four subgroups. RESULTS: The IOP of the pregnant group (primigravidae and multigravidae together) was (mean+/-SEM) 2. 1+/-0.07 mmHg (P<0.001) lower than in the nulligravida control group. The IOP of nulligravidae was 1.7+/-0.06 mmHg (P<0.001) and 2.5+/-0. 01 mmHg (P<0.001) higher than in third-trimester primigravidae and multigravidae, respectively. In all subgroups of multigravidae IOP was significantly lower (P<0.02) than in primigravidae. The differences among different subgroups of multigravidae were statistically insignificant. CONCLUSIONS: Gravidity influences IOP and should be taken into account in future research.

Adult↗

PubMed1999

Hyperlipidaemia during normal pregnancy, parturition and lactation.

Excessive accumulation of one or more of the major lipids in plasma can produce a marked increase in the risk of coronary heart diseases and other vascular complications. During and after pregnancy, changes in the levels of total cholesterol, triglyceride, low density lipoprotein-cholesterol, and high density lipoprotein-cholesterol have been described, but the amount of change varies from study to study. Therefore, the present study investigated changes in lipids and lipoproteins throughout the pregnancy and puerperium. We also investigated for the factors which may affect the plasma lipids during pregnancy. Concentrations of cholesterol and triglyceride of total plasma and lipoproteins were determined in 42 pregnant women throughout their pregnancy and puerperium together with a control group of 42 non-pregnant women. Compared to the control group, concentrations of cholesterol and triglyceride of total plasma and lipoproteins increased significantly during the second trimester and reached maximum in the third trimester. Concentrations of both, cholesterol and triglyceride, decreased significantly during post-partum. There was, however, a strikingly more rapid fall of plasma triglyceride and cholesterol in those mothers who breast-fed their infants compared with that in those in whom lactation was never established. In the majority of subjects, cholesterol and triglycerides remained significantly high until the fourth week of post-partum. The magnitude of the plasma cholesterol increment appeared in part to be related to that of plasma triglycerides, but these increments appeared to be independent of age, weight gain, numbers of previous pregnancies and sex of the foetus. This study concludes that hyperlipidaemia is a common finding during pregnancy and during post-partum. The concentrations of both cholesterol and triglycerides remain significantly higher in bottle-feeding than in breast-feeding mothers.

Adult↗

PubMed1999

Hyperlipidemia of normal pregnancy in Karachi-Pakistan.

During pregnancy, changes in the levels of total cholesterol, triglyceride, low density lipoprotein-cholesterol, and high density lipoprotein-cholesterol have been described, but in the existing literature these effects remain controversial because of inconsistencies. Moreover, the degree of change varies from study to study. Therefore, the present study completely investigated changes in lipids and lipoproteins throughout the pregnancy and in the puerperium. We also investigated whether or not any relation between plasma lipids and other pregnancy related factors exist. Concentrations of cholesterol and triglyceride of total plasma, and lipoproteins were determined in 56 pregnant women throughout the pregnancy and in the puerperium along with 56 non-pregnant women. Compared to control group, concentrations of cholesterol and triglyceride of total plasma and lipoproteins increased significantly during second trimester and reached maximum in the third trimester. Both cholesterol and triglyceride concentrations decreased significantly within 24 hours of delivery and this was reflected in all lipoproteins. In the majority of subjects, cholesterol and triglycerides remained significantly high until 4 weeks of postpartum. The magnitude of the serum cholesterol increment appeared in part to be related to that of serum triglyceride, but these increments appeared to be independent of age, weight gain, numbers of previous pregnancies and sex of the fetus. This study concludes that hyperlipidemia is a common finding during pregnancy.

Arteriosclerosis↗

PubMed1998

Variations in ocular pressure during menstrual cycle.

The present study investigated whether a correlation between days of the menstrual cycle and variations in intraocular pressure exists or not. The number of days since the beginning of last menses was recorded along with intraocular pressure for 1,459 women. Measurements were taken by Goldmann applanation tonometer. The differences among various days of menstrual cycle were statistically insignificant. The highest mean IOP occurred between 20th and 22nd day and the second peak from 13th to 15th days of the cycle. The lowest mean IOP was found from 16th to 19th days of the cycle. This study concludes that intraocular pressure varies with the various days of the menstrual cycle, but fluctuations are statistically insignificant and cannot affect the diagnoses of glaucoma.

Female↗

PubMed1997

Resting intraocular pressure of steel factory workers is related to their physical fitness.

Intraocular pressure (IOP) has never been compared between hard working and sedentary subjects. The relationship between physical fitness and IOP is not clearly known. There are only two studies and their results are contradictory. The variability in their results may be due to several factors. Therefore, the present study was planned to investigate the relationship between working style, physical fitness and IOP after taking into account those factors that can affect IOP. One hundred fifty male volunteers of a steel factory were divided equally in two groups. The subjects of group 1 were sedentary worker, whereas group 2 subjects were actively engaged in heavy works requiring exertion. Physical fitness was evaluated by the measurement of maximum oxygen uptake with a Bechman O2 analyzer. IOP was measured with the Goldmann applanation tonometer. As compared to sedentary subjects, maximum oxygen uptake was significantly higher whereas IOP was significantly lower in those who did moderate or severe exertions. The maximum oxygen uptake difference between group 1 and 2 was found to be (mean +/- SD) 5.1 +/- 1.1 ml/kg/min (p < 0.001), whereas, IOP difference was 1.9 +/- 0.7 mmHg (p < 0.001). This study concludes that hard working is associated with physical fitness and physical fitness is associated with reduced resting IOP. It would seem reasonable at present not to discourage subjects who have ocular hypertension from exercise; perhaps, on the contrary, it should be encouraged to increase their physical fitness.

Humans↗

PubMed1997

Effect of third trimester of pregnancy on diurnal variation of ocular pressure.

This study was planned to evaluate the effect of pregnancy on diurnal variation of intraocular pressure (IOP) after placing control on all the IOP affecting factors. The IOP was measured with the Goldmann applanation tonometer. Both in the control and 3rd trimester subjects, the peak of mean IOP appeared in the morning when the subjects waked, and the trough of mean IOP happened at 2 am to 4 am. The diurnal intraocular pressure curves revealed that the IOP peaks were 15.4 +/- 0.9 and 12.9 +/- 0.6 mmHg in the control and third trimester pregnant subjects, respectively. Whereas the trough were 13.1 +/- 0.4 and 11.8 +/- 0.3 mmHg, respectively. The mean diurnal variation were 2.3 +/- 0.6 mmHg (P < 0.01), and 1.1 +/- 0.8 mmHg in the control and third trimester subjects, respectively. There are two main findings of present study: first, compared with non-pregnant control subjects, the IOP was significantly lower (P < 0.001) in the third trimester pregnant subjects. Second, in the third trimester of pregnancy, the lower IOP level was associated with the less degree of IOP fluctuations at various hours of the day.

Circadian Rhythm↗

PubMed1997

Hormonal changes associated with menstrual cycle have no definite influence on ocular pressure.

BACKGROUND: Despite some findings to the contrary, it would appear that pharmacological doses of progesterone and estrogen (alone or in combination) can influence intraocular pressure (IOP). The relationship between hormonal changes associated with the menstrual cycle and intraocular pressure is not clearly understood. After elimination of those factors that can affect IOP, the present study investigated whether physiological hormonal changes associated with the menstrual cycle have a correlation with intraocular pressure. METHODS: Intraocular pressure and the concentrations of circulating hormones, namely, the luteinizing hormone (LH), follicle-stimulating hormone (FSH), estrone (E1), estradiol (E2), progesterone, and testosterone, of twenty married women of the same age groups were recorded daily throughout a menstrual cycle. None was taking any contraceptives in any form. The intraocular pressure was measured using a Goldmann applanation tonometer. RESULTS: The intraocular pressure values fluctuated in each of the twenty subjects at various times of the cycle; however, they were not definitely correlated with the different phases of the cycle. This study failed to find any correlation between IOP and progesterone or estradiol levels.

Adult↗

PubMed1997

The effect of exercise training on physical fitness and plasma lipids in young Chinese men and women.

BACKGROUND: The mortality from coronary heart disease (CHD) has been steadily increasing in many parts of the world. Measures to reduce the incidence of CHD were initially addressed mainly to middle aged and elderly population groups, but for effective prevention of CHD, measures addressed to younger age groups are also necessary. Moreover, differences between male and female plasma lipid changes after exercise training are not known exactly. METHODS: The concentrations of plasma lipids, before and after regular physical exercise training for 12 weeks, were analyzed in 25 male and 25 female medical students of the same age group. Physical fitness was evaluated by the measurement of maximum oxygen uptake. RESULTS: Results indicated that plasma tri-glyceride, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol differences between the before-and-after exercise were significant (p < 0.05) in males while the differences of plasma total cholesterol were found to be insignificant. In females there were no significant changes in the plasma lipids levels. In both males and females, the marked increase in maximal O2 uptake after exercise training indicated an improvement in physical fitness. CONCLUSIONS: This study concludes that a short-term exercise program can improve plasma lipid and lipoprotein patterns more in males than in females. It also suggests that daily physical exercise may be an important prevention for cardiovascular diseases in later life, so it is essential to establish a life style with optimum nutrition and physical activity in both the young and in adults of all ages.

Adult↗

PubMed1997

Monthly measurements of intraocular pressure in normal, ocular hypertensive, and glaucoma male subjects of same age group.

BACKGROUND: Recently it has been shown that environmental conditions have a significant influence on intraocular pressure (IOP). Due to differences in inherent constitution, diet and environmental conditions, there is a clear need for well collected IOP data in different countries and ethnic groups. The seasonal variation of IOP has never been described in Pakistani subjects. METHODS: IOP was measured each month over the course of 12 months with the Goldmann applanation tonometer in normal, ocular hypertensive, and glaucoma male subjects. RESULTS: In all groups, the average intraocular pressures in the winter months were highest, while lowest in summer months. The intraocular pressures of spring and autumn months were nearly the same. The intraocular pressure levels in these seasons were between the IOP levels in summer and winter seasons. The difference between highest and lowest IOP was 1.4 +/- 0.2, 3.1 +/- 1.4, and 2.3 +/- 1.1 mmHg, in normal, ocular hypertensive, and glaucoma subjects, respectively. The ups and downs of intraocular pressure were greater in the ocular hypertensive subjects than in the glaucoma patients. CONCLUSIONS: This study confirms that season influences IOP, and concludes that seasonal influence is highest in ocular hypertensive than in normal and glaucoma subjects. As compared to other nations, effect of seasons on IOP seems to be somewhat less pronounced in Pakistan.

Glaucoma↗

PubMed1996

Intraocular pressure trends in pregnancy and in the third trimester hypertensive patients.

BACKGROUND: Systemic blood pressure is positively related to intraocular pressure. During the third trimester of pregnancy decreased intraocular pressure while increased blood pressure has been reported. After taking into account all those factors that can affect intraocular pressure, the present study investigated whether or not the high blood pressure found in late pregnancy influences the known ocular hypotensive effect of late pregnancy. SUBJECTS AND METHODS: Normotensive subjects in all trimesters of pregnancy and non-pregnant control groups along with third trimester hypertensive subjects were studied. Intraocular pressure was measured with the Goldmann applanation tonometer. RESULTS: In the second and third trimester subjects, the mean intraocular pressure was significantly lower than in the non-pregnant control group. The differences between first and second, first and third, and second and third trimesters of pregnancy were (mean +/- s.d.) -0.5 +/- 1.2 (p < 0.05), -1.5 +/- 1.7 (p < 0.001), and -1.0 +/- 2.1 (p < 0.01) mmHg respectively. The mean difference between third trimester hypertensive and third trimester normotensive pregnant women was 0.53 +/- 1.5 mmHg (p < 0.05). CONCLUSIONS: With advancing pregnancy, intraocular pressure decreases. The mean intraocular pressures of third trimester hypertensive pregnant women were significantly higher from that of third trimester non-hypertensives. Knowledge of the normal level of intraocular pressure in various stages of pregnancy may help glaucoma screeners.

Adult↗

PubMed1996

Effect of seasons upon intraocular pressure in healthy population of China.

Studies have been shown that intraocular pressure (IOP) shows a seasonal variation, but amount of change differs from study to study. The variability in their results may be due to negligence of factors that can affect IOP. Due to differences in environmental conditions of China than other countries, we investigated seasonal variations in IOP of 103 healthy male Chinese of Shanghai. IOP was measured each month over the course of fourteen months with the Goldmann applanation tonometer. The average intraocular pressures in the winter months were higher than those in the spring, summer, and autumn months. The IOP difference between winter and summer months was found to be 1.4 +/- 0.7 mmHg. This study confirms that season influences IOP. As compared to other nations, effect of seasons on IOP seems to be somewhat less pronounced in Chinese. The possible mechanisms, responsible for the seasonal variation of intraocular pressure, are also postulated.

Adult↗

PubMed1996

Magnitude of decrease in intraocular pressure depends upon intensity of exercise.

The present study was planned to investigate the relationship between the magnitude of intraocular pressure (IOP) reduction after short-duration exercise and the intensity, duration and quantity of exercise in healthy subjects. Twenty-five healthy, sedentary male of the same age group, performed exercises at the levels of 80%, 60%, and 40% maximum heart rate (HRmax) for 15 minutes, 80% HRmax for 7.5 minutes, 60% HRmax for 10 minutes, and 40% HRmax for 30 minutes. IOP was measured with the Goldmann applanation tonometer. The IOP reduction at 5 minutes after 15 minutes of exercising at 80% HRmax, 60% HRmax, and 40% HRmax were 4.7 +/- 0.9, 3.5 +/- 0.7, and 0.9 +/- 0.4 mmHg, respectively. At five minutes, after exercising 7.5 minutes at 80% HRmax, 10 minutes at 60% HRmax, and 30 minutes at 40% HRmax, IOP reduced by 4.5 +/- 0.7, 3.3 +/- 0.9, and 2.9 +/- 1.1 mmHg, respectively. This study concludes that intensity of exercise seems responsible for the magnitude of the initial IOP decrease after short-term exercise. Furthermore, it seems that other factors such as duration of exercise or quantity of exercise, blood pressures, body mass index are not related to the amount of the initial fall in IOP.

Adult↗

PubMed1996

Effect of physical fitness on plasma lipids in young Chinese adults.

Epidemiological studies indicate that individuals with more physically demanding occupations or leisure time activities generally have a lower rate of coronary heart disease (CHD) than those that are more sedentary. Physical exercise may alleviate the risk factors of CHD. Previous literature regarding the effects of exercise upon triglycerides and cholesterol is contradictory. This study compares the effects of regular physical exercise on the concentration of plasma lipids of thirty male medical students, ages ranging between 21 and 30 years. The diet of all the subjects was nearly the same during the last four years. The subjects participated in a voluntary program of exercise for ten weeks. The differences between before and after the exercises were found to be -0.13 +/- 0.04, -0.13 +/- 0.08, 0.21 +/- 0.05, -0.10 +/- 0.04, -0.02 +/- 0.01 mmol/L of triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol (mean +/- SEM), respectively. The differences between triglycerides, HDL-cholesterol, and LDL-cholesterol were significant (p < 0.05), meanwhile, the differences between total cholesterol and VLDL-cholesterol were insignificant. The marked increase in maximal O2 uptakes after exercise training of ten weeks indicates a significant improvement in the subjects' physical fitness. Based on the results in this study, we can conclude that daily physical exercise may be an effective inhibitor for cardiovascular diseases in later life, thereby necessitating a strategy for physical activity in young adults.

Adult↗

PubMed1996

Diurnal variation of intraocular pressure in normal and ocular hypertensive subjects of China.

This study evaluated the distribution of Intraocular pressure (IOP) levels in 67 normal and 59 ocular hypertensive (OHT) subjects during the day after placing control on all those factors that can affect IOP. The IOP was measured with the Goldmann applanation tonometer. All the subjects were examined according to standard protocols. Both in the normal and OHT subjects, the peak of mean IOP appeared in the morning when the subjects woke up and the trough of mean IOP occurred between 2 a.m. to 4 a.m. The mean diurnal variation were (mean +/- sem) 2.9 +/- 0.7 and 3.5 +/- 0.7 mmHg in the normal and in OHT subjects, respectively. Ninety-four percent of the normal subjects and sixty-eight percent of the OHT subjects exhibited a similar diurnal behaviour in both eyes. The IOP variation did not correlate with the variations of blood pressure. The diurnal variation of IOP, found in Chinese, is lower than in other nations. The clinical importance of findings that the peaks of IOP occur in the early morning, raised a serious question as to the necessity of extending the diurnal IOP curves beyond the usual working time (JPMA 46:171, 1996).

Adult↗

PubMed1996

Distribution of intraocular pressure among healthy Pakistani.

Because the course of glaucoma is often an insidious one and most cases remain asymptomatic until the visual field has been clearly diminished, the frequency distribution of intraocular pressure (IOP) is important from both an academic and clinical viewpoint. However, diagnostically, glaucoma is a disease suited to a preventive approach. Due to differences in intrinsic constitution, diet and environmental conditions, there is a clear need for well collected population-based IOP data in different countries. In the present study, after controlling for the factors that can effect IOP, we investigated the distribution of intraocular pressure in 7201 healthy subjects of both sexes of Karachi, Pakistan. In both sexes, distribution of IOP slightly skewed towards the higher values. In males and females, 85.1% and 82.2% individuals ranged from 11 to 18 mmHg, 4.3% and 3.2% ranged from 8 to 10 mmHg, 7.1% and 11.2% ranged from 19 to 21 mmHg, respectively. Ocular hypertension (IOP > 21 mmHg) was found in 3.5% males and 3.7% females. Intraocular pressure increased with age in both eyes of both sexes. The averages per decade increase were 0.3 mmHg and 0.5 mmHg in male and female respectively. This study reports that an average per decade increase, women have 0.4 mmHg higher IOP than men. The male-female difference was not statistically significant until the age groups reached 31-40 years, after which the differences became significant. Right and left eyes IOPs were found to be 14.3 +/- 0.17 and 14.4 +/- 0.12 mmHg in male and 14.6 +/- 0.14 and 14.8 +/- 0.15 mmHg in females respectively. This survey shows that mean IOP of Pakistani population is similar to the IOP found in other epidemiologic investigations; the prevalence of ocular hypertension, however, seems to be slightly higher. Knowledge of the normal level of IOP in various age groups of both sexes will help to screen glaucoma.

Adolescent↗

PubMed1996

The effect of physical fitness on intraocular pressure in Chinese medical students.

BACKGROUND: Virtually all the tissues and systems of the human body have been shown to be responsive to programs of exercise. Regarding the relationship between physical fitness and intraocular pressure (IOP), the existing literature is controversial with some associations inconsistent. In one study, IOP values were not dependent upon changes in physical fitness. In contrast to this, another study demonstrated that physical fitness significantly reduces intraocular pressure levels. In recent years it has been noted that intraocular pressure is a dynamic function and is subject to many influences both acutely and over the long term. The variety of results of previous studies may have come from several factors which can affect intraocular pressure. The present study was planned to investigate the effects of physical fitness on intraocular pressure in Chinese medical studies, after elimination of other affecting factors. METHODS: Forty medical students were categorized into control and experimental groups, each consisting of 20 subjects. The experimental group took a supervised exercise program for 10 weeks. Physical fitness was evaluated by measurement of maximum oxygen uptake with a Beckman O2 analyzer. Intraocular pressure was measured with the Goldmann applanation tonometer. RESULTS: After exercise training, the experimental group showed a marked increase in physical fitness. The difference of IOP between the control and experimental groups before exercise conditioning was 0.3 +/- 0.1 mmHg (P > 0.05). After 10 weeks, this difference increased to 1.1 +/- 0.4 mmHg (p < 0.05). CONCLUSIONS: This study concludes that physical fitness reduces intraocular pressure. Whether exercise conditioning has a role as a nonpharmacologic approach or as an addition to medical therapy must be left to future investigations.

Adult↗