Biomedical subjects

G C Curhan

Publications and source records attributed to G C Curhan.

At least 19 recordsLinked to original sources

PubMed2000

A prospective study of age and lifestyle factors in relation to community-acquired pneumonia in US men and women.

BACKGROUND: Information is limited on risk factors for community-acquired pneumonia (CAP) in free-living populations. We examined the associations of age, smoking status, body mass index (BMI), weight change during adulthood, physical activity, and alcohol intake with risk of CAP among men and women. METHODS: The study population included 26,429 men aged 44 to 79 years from the Health Professionals Follow-up Study and 78,062 women aged 27 to 44 years from the Nurses' Health Study II. Information was collected by biennial mailed questionnaires and the main outcome was physician-diagnosed incident pneumonia. RESULTS: There were 290 cases among men (6 years of follow-up) and 305 cases among women (2 years of follow-up). Age, smoking status, BMI, physical activity, and alcohol intake were taken into account in the multivariate logistic regression model. There was a dose-response relation between aging and risk of CAP among men. Compared with never smokers, current smoking was associated with risk of CAP among men (relative risk, 1.46; 95% confidence interval, 1.00-2.14) and women (relative risk, 1.55; 95% confidence interval, 1.15-2.10). In addition, BMI was directly associated with an increased risk of CAP among women. Compared with the participants who maintained their weight during adulthood, the risks were nearly 2-fold higher among men and women who gained 40 lb or more (> or =18 kg). The risk of CAP decreased with increasing physical activity among women. We also found no significant relation between alcohol intake and risk of CAP among men and women. CONCLUSIONS: Smoking and excessive weight gain are risk factors for CAP among men and women, and physical activity was inversely associated with risk of CAP only among women. The incidence of CAP could possibly be decreased by lifestyle factors.

Adult↗

PubMed2000

Relationship between nonphenacetin combined analgesics and nephropathy: a review. Ad Hoc Committee of the International Study Group on Analgesics and Nephropathy.

BACKGROUND: The debate on the association between nonphenacetin-containing combined analgesics and renal disease has lasted for several years. METHOD: A peer review committee of scientists, selected jointly by the regulatory authorities of Germany, Switzerland, and Austria and the pharmaceutical industry was asked to critically review data on the relationship between nonphenacetin combined analgesics and nephropathy. RESULTS: The committee regarded epidemiologic evidence on nonphenacetin combined analgesics as inconclusive because of sparse information and substantial methodological problems. The committee also noted that a diagnosis of analgesic-associated nephropathy (AAN) in clinical practice usually depends on information about exposure before or in the early stages of the disease and is seldom accompanied by specific histologic evidence. The morphologic finding of papillary calcification can arise from other conditions and is not specific for AAN. For these reasons, the identification criteria for AAN should be reappraised with scientific methods to validate the diagnostic procedure. In the limited amount of experimental pharmacological data in humans and animals, the committee found no convincing evidence to confirm or refute the hypothesis that nonphenacetin combined analgesics are more nephrotoxic than single formulations. For caffeine taken with combined analgesics, the currently available information is not sufficient to postulate a harmful toxicological effect. CONCLUSION: The committee's two main conclusions were that sufficient evidence is absent to associate nonphenacetin combined analgesics with nephropathy and that new studies should be done to provide appropriate data for resolving the question.

Acetaminophen↗

PubMed2000

Diabetes, hemoglobin A(1c), cholesterol, and the risk of moderate chronic renal insufficiency in an ambulatory population.

Moderate chronic renal insufficiency is common, with 12.5 million individuals in the United States estimated to have a creatinine clearance less than 50 mL/min/1.73 m(2). Little is known about the risk factors for moderate chronic renal insufficiency. We studied 1, 428 subjects with Cockcroft-Gault-estimated creatinine clearances greater than 70 mL/min in a hospital-based ambulatory population. Over a mean of 5.7 +/- 1.3 years, 86 subjects developed moderate chronic renal insufficiency, defined as a decrease in creatinine clearance to less than 60 mL/min (1.1 case/100 person-years). Risk factors for moderate chronic renal insufficiency were identified using a proportional hazards model controlling for age, sex, race, systolic blood pressure, and angiotensin-converting enzyme (ACE) inhibitor use. The risk for developing moderate chronic renal insufficiency was associated with diabetes mellitus (relative risk, 2.1; 95% confidence interval [CI], 1.3 to 3.3) and elevated hemoglobin A(1c) levels. Compared with subjects with normoglycemia (hemoglobin A(1c) </= 5.7%), the relative risk for moderate chronic renal insufficiency for patients in the upper quartile of hemoglobin A(1c) (>9.0%) was 2.7 (95% CI, 1.4 to 5.1). The development of moderate chronic renal insufficiency was also independently predicted by elevated maximum serum cholesterol level. Compared with subjects with maximum cholesterol levels of 250 mg/dL or less, the relative risk for those with maximum cholesterol levels greater than 350 mg/dL was 2.4 (95% CI, 1.1 to 5.2). Similar relative risks were obtained when moderate chronic renal insufficiency was defined by the development of an increase in serum creatinine level. Hypercholesterolemia was also associated with moderate chronic renal insufficiency among persons without diabetes. In conclusion, the risk for developing moderate chronic renal insufficiency is increased by diabetes and elevated hemoglobin A(1c) and serum cholesterol levels. Modification of these risk factors may decrease the incidence of moderate chronic renal insufficiency.

Cholesterol↗

PubMed2000

Quality of life among women with interstitial cystitis.

PURPOSE: Clinical case series suggest that the impact of interstitial cystitis on quality of life is severe and debilitating, however, little epidemiologic information is available. We examined the impact of interstitial cystitis on quality of life in a population based cohort of United States women. MATERIALS AND METHODS: We collected multidimensional measures of quality of life from 159,419 participants in the Nurses' Health Study I and II using a validated instrument, the Medical Outcome Study Short-Form 36 Health Survey Instrument. This instrument measures physical function, role limitations due to physical and emotional problems, bodily pain, vitality, social function and mental health. Quality of life measures were collected on 99 women with prevalent self reported interstitial cystitis confirmed by medical record review. RESULTS: After adjusting for age and co-morbid conditions, women with interstitial cystitis had significantly lower quality of life scores in 4 of the 7 quality of life dimensions, including role/physical (beta -13.1, p <0.001), bodily pain (beta -9.8, p <0.001), vitality (beta -7.7, p <0.001) and social function (beta -7.2, p <0.001) compared to women without interstitial cystitis. Women with interstitial cystitis experienced less decrement in physical function compared to women with rheumatoid arthritis but more compared to women with hypertension. In addition, they experienced greater differences in vitality and mental health than women with rheumatoid arthritis or hypertension. CONCLUSIONS: The quality of life among women with interstitial cystitis was especially limited in the psychosocial dimensions, such as vitality and mental health. Future research on interstitial cystitis should incorporate multidimensional measures of quality of life, especially with respect to response to the various treatments.

Adult↗

PubMed1999

Fluid intake and the risk of bladder cancer in men.

BACKGROUND: Studies in animals have shown that the frequency of urination is inversely associated with the level of potential carcinogens in the urothelium. In humans, an increase in total fluid intake may reduce contact time between carcinogens and urothelium by diluting urinary metabolites and increasing the frequency of voiding. The data on fluid intake in relation to the risk of bladder cancer are inconclusive. METHODS: We examined the relation between total fluid intake and the risk of bladder cancer over a period of 10 years among 47,909 participants in the prospective Health Professionals Follow-up Study. There were 252 newly diagnosed cases of bladder cancer during the follow-up period. Information on total fluid intake was derived from the reported frequency of consumption of the 22 types of beverages on the food-frequency questionnaire, which was completed by each of the 47,909 participants who were free of cancer in 1986. Logistic-regression analyses were performed to adjust for known and suspected risk factors for bladder cancer. RESULTS: Total daily fluid intake was inversely associated with the risk of bladder cancer; the multivariate relative risk was 0.51 (95 percent confidence interval, 0.32 to 0.80) for the highest quintile of total daily fluid intake (>2531 ml per day) as compared with the lowest quintile (<1290 ml per day). The consumption of water contributed to a lower risk (relative risk, 0.49 [95 percent confidence interval, 0.28 to 0.86] for > or =1440 ml [6 cups] per day vs. <240 ml [1 cup] per day), as did the consumption of other fluids (relative risk, 0.63 [95 percent confidence interval, 0.39 to 0.99] for >1831 ml per day vs. <735 ml per day). CONCLUSIONS: A high fluid intake is associated with a decreased risk of bladder cancer in men.

Adult↗

PubMed1999

A prospective study of pregravid oral contraceptive use and risk of hypertensive disorders of pregnancy.

Oral contraceptive use is associated with hypertension, dyslipidemias, and insulin resistance, all of which also characterize hypertensive disorders of pregnancy. In this prospective cohort study, the association of oral contraceptive use before pregnancy and the risk of gestational hypertension and preeclampsia was assessed. Between 1991 and 1995, 3973 nulliparous women who reported their first pregnancy lasting > or = 6 months were studied. Pregravid exposures were collected by biennial mailed questionnaires, and cases were confirmed by medical record review. Recent oral contraceptive use was defined as use within 2 years of pregnancy. Proportional hazards analysis was used to adjust for potential confounding variables. During the 4 years of follow-up, 133 (3.3%) women with gestational hypertension and 62 (1.6%) with preeclampsia were identified. Twenty-five percent of women who did not develop these disorders were recent users of oral contraceptives, compared with 19% (p = 0.11) of women who developed gestational hypertension and 30% (p = 0.38) who developed preeclampsia. Mean duration of prior oral contraceptive use was similar for cases and noncases. Compared with never and past users, the multivariate relative risk among recent users for developing gestational hypertension was 0.7 (95% confidence interval (CI), 0.4-1.0) and for preeclampsia was 1.3 (95% CI, 0.8-2.4). Among recent users who had used oral contraceptives for > or = 8 years, the relative risk for gestational hypertension was 0.6 (95% CI, 0.3-1.2) and for preeclampsia was 2.1 (95% CI, 1.1-4.2). When the analysis was restricted to women who had never smoked, the risk for gestational hypertension was 0.2 (95% CI, 0.1-0.9) and for preeclampsia was 4.1 (95% CI, 1.9-8.7). Thus, recent use of oral contraceptives was associated with a reduced risk for developing gestational hypertension. In contrast, there was a suggestion that recent use was associated with an increased risk of developing preeclampsia, but only among women who had used these agents for > or = 8 years.

Adult↗

PubMed1999

High body mass index and hypercholesterolemia: risk of hypertensive disorders of pregnancy.

OBJECTIVE: To examine the relationship between pregravid body mass index (BMI), elevated cholesterol level, and the development of hypertensive disorders of pregnancy. METHODS: We studied 15,262 women who gave birth between 1991 and 1995. Pregravid exposures including BMI and self-reported history of elevated cholesterol were ascertained by biennial mailed questionnaires. Gestational hypertension or preeclampsia was confirmed by medical record review according to standard criteria. Proportional hazards analysis was used to adjust for potential confounding variables. RESULTS: We confirmed 216 cases of gestational hypertension and 86 cases of preeclampsia. The risk of gestational hypertension increased as pregravid BMI increased (P < .01). Compared with women with a pregravid BMI of 21-22.9 kg/m2, the relative risk (RR) of gestational hypertension was 1.6 (95% confidence interval [CI] 1.0, 2.3) for women with BMI of 23-24.9 kg/m2, 2.0 (95% CI 1.3, 3.0) for BMI 25-29.9 kg/m2, and 2.6 (95% CI 1.6, 4.4) for BMI over 30 kg/m2. Leaner women (BMI less than 21 kg/m2) had a reduced risk (RR 0.7, 95% CI 0.4, 1.0). For preeclampsia, the RR of women with pregravid BMI over 30 kg/m2 was 2.1 (95% CI 1.0, 4.6) (P for trend 0.09). A history of elevated cholesterol was not associated with the risk of gestational hypertension (RR 0.9, 95% CI, 0.6, 1.4). In contrast, the RR of preeclampsia in women with a history of elevated cholesterol was 2.0 (95% CI 1.2, 3.3). CONCLUSION: Pregravid BMI and hypercholesterolemia could identify women at higher risk for hypertensive disorders during pregnancy.

Adult↗

PubMed1999

Epidemiologic evidence for the role of oxalate in idiopathic nephrolithiasis.

The importance of dietary and urinary oxalate in the formation of calcium oxalate kidney stones is widely accepted. Although the epidemiologic evidence for the role of oxalate remains largely indirect, recent prospective observations suggest its importance. The inverse association between dietary calcium intake and the risk of stone formation may be attributable to decreased gastrointestinal absorption of dietary oxalate and, thus, lower urinary oxalate concentrations. Further, the decreased risk of stone formation in women who consume large doses of vitamin B6 may be secondary to decreased oxalate production. The increased risk of nephrolithiasis observed with increasing body size may also be secondary to increased endogenous oxalate production. However, the frequency of hyperoxaluria is not substantially different in cases and controls for either sex. Notably, men have both higher stone incidence rates and higher mean urinary oxalate concentrations than women. Additional studies are needed to determine more precisely the role of dietary oxalate. More valid and comprehensive information on the oxalate content of food are desperately needed. Because the data on dietary oxalate are inconclusive, the routine restriction of dietary oxalate needs to be reexamined.

Calcium Oxalate↗

PubMed1999

Intake of vitamins B6 and C and the risk of kidney stones in women.

Urinary oxalate is an important determinant of calcium oxalate kidney stone formation. High doses of vitamin B6 may decrease oxalate production, whereas vitamin C can be metabolized to oxalate. This study was conducted to examine the association between the intakes of vitamins B6 and C and risk of kidney stone formation in women. The relation between the intake of vitamins B6 and C and the risk of symptomatic kidney stones were prospectively studied in a cohort of 85,557 women with no history of kidney stones. Semiquantitative food-frequency questionnaires were used to assess vitamin consumption from both foods and supplements. A total of 1078 incident cases of kidney stones was documented during the 14-yr follow-up period. A high intake of vitamin B6 was inversely associated with risk of stone formation. After adjusting for other dietary factors, the relative risk of incident stone formation for women in the highest category of B6 intake (> or =40 mg/d) compared with the lowest category (<3 mg/d) was 0.66 (95% confidence interval, 0.44 to 0.98). In contrast, vitamin C intake was not associated with risk. The multivariate relative risk for women in the highest category of vitamin C intake (> or =1500 mg/d) compared with the lowest category (<250 mg/d) was 1.06 (95% confidence interval, 0.69 to 1.64). Large doses of vitamin B6 may reduce the risk of kidney stone formation in women. Routine restriction of vitamin C to prevent stone formation appears unwarranted.

Adult↗

PubMed1999

Epidemiology of interstitial cystitis: a population based study.

PURPOSE: Interstitial cystitis is a chronic and debilitating syndrome but surprisingly little is known about its epidemiology. This study was designed to estimate the prevalence of interstitial cystitis among women in the United States. MATERIALS AND METHODS: Female participants in the Nurses' Health Study (NHS) I and II (184,583) were asked by mailed questionnaires whether they had ever been diagnosed with interstitial cystitis. We requested and reviewed medical records of women self-reporting interstitial cystitis. The accuracy of self-reports was evaluated using standardized criteria. RESULTS: Among the 93,428 women who responded to the NHS II questionnaire and 91,155 women who responded to the NHS I questionnaire 1,354 (1.4%) and 357 (0.4%), respectively, self-reported interstitial cystitis. Based on medical record review 63 cases of interstitial cystitis were confirmed in NHS II and 47 in NHS I. The prevalence of interstitial cystitis was 67/100,000 women in NHS II and 52/100,000 in NHS I. There was no substantial variation in prevalence by age. CONCLUSIONS: The prevalence of interstitial cystitis in the United States is more than 50% greater than previously reported and 3-fold greater than that reported in Europe.

Adult↗

PubMed1998

Retrospective analysis of birth weight and prostate cancer in the Health Professionals Follow-up Study.

The authors retrospectively evaluated the relation between birth weight and prostate cancer (1986-1994) among 21,140 men of the Health Professionals Follow-up Study who reported in 1994 their weight at birth. No relation between birth weight and prostate cancer (n=545) was observed in multivariate logistic models. For high stage/grade tumors (n=213), compared with birth weights <7.0 lbs (<3,175 g), the relative risks were 1.20 (95% confidence interval (CI) 0.79-1.83) for 8.5-9.9 lbs (3,855.6-4,490.6 g) and 1.30 (95% CI 0.80-2.10) for > or = 10 lbs (> or = 4,536 g). These findings do not support an overall association between birth weight and prostate cancer incidence, but the possibility of a modest positive association between birth weight and high stage/grade prostatic cancer cannot be excluded.

Adult↗

PubMed1998

Beverage use and risk for kidney stones in women.

BACKGROUND: An increase in fluid intake is routinely recommended for patients who have had kidney stones to decrease the likelihood of recurrence. However, data on the effect of particular beverages on stone formation in women are limited. OBJECTIVE: To examine the association between the intake of 17 beverages and risk for kidney stones in women. DESIGN: Prospective cohort study with 8 years of follow-up. SETTING: United States. PARTICIPANTS: 81093 women in the Nurses' Health Study who were 40 to 65 years of age in 1986 and had no history of kidney stones. MEASUREMENTS: Beverage use and diet were assessed in 1986 and 1990 with a validated, self-administered food-frequency questionnaire. The main outcome measure was incident symptomatic kidney stones. RESULTS: During 553 081 person-years of follow-up over an 8-year period, 719 cases of kidney stones were documented. After risk factors other than fluid intake were controlled for, the relative risk for stone formation for women in the highest quintile of total fluid intake compared with women in the lowest quintile was 0.62 (95% CI, 0.48 to 0.80). Inclusion of consumption of specific beverages in the multivariate model significantly added to prediction of risk for kidney stones (P < 0.001). In a multivariate model that adjusted simultaneously for the 17 beverages and other possible risk factors, risk for stone formation decreased by the following amount for each 240-mL (8-oz) serving consumed daily: 10% (CI, 5% to 15%) for caffeinated coffee, 9% (CI, 2% to 15%) for decaffeinated coffee, 8% (CI, 1% to 15%) for tea, and 59% (CI, 32% to 75%) for wine. In contrast, a 44% (CI, 9% to 92%) increase in risk was seen for each 240-mL serving of grapefruit juice consumed daily. CONCLUSIONS: An increase in total fluid intake can reduce risk for kidney stones, and the choice of beverage may be meaningful.

Adult↗

PubMed1998

Nephrolithiasis and risk of hypertension in women.

Cross-sectional and prospective studies of men suggest a positive association between nephrolithiasis and hypertension. However, this association remains controversial in women. We conducted a prospective study of the relation between nephrolithiasis and the risk for hypertension in the Nurses' Health Study, a cohort of 89,376 women aged 34 to 59 years in 1980. Information on the history of nephrolithiasis, physician-diagnosed hypertension, and other relevant exposures was obtained by biennial mailed questionnaire. A history of nephrolithiasis before 1980 was reported by 2,558 women (2.9%), and a history of hypertension was reported by 11,883 women (13.3%). Among women without hypertension before 1980, 12,540 women reported a new diagnosis of hypertension between 1980 and 1992, during 711,039 person-years of follow-up. Compared with those without a history of nephrolithiasis, the age-adjusted relative risk (RR) for incident hypertension in women with such a history was 1.36 (95% confidence interval [CI], 1.20 to 1.43). After further adjustment for body mass index (BMI) and the intake of calcium, sodium, potassium, magnesium, caffeine, and alcohol, the RR was only slightly attenuated (RR=1.24; 95% CI, 1.13 to 1.37). In contrast, the occurrence of incident nephrolithiasis during follow-up was similar in women with hypertension at baseline compared with women without (adjusted odds ratio [OR]=1.01; 95% CI, 0.85 to 1.20). These data are consistent with the results obtained in men and support the hypothesis that a history of nephrolithiasis is associated with an increased risk for subsequent hypertension. Dietary factors, such as the intake of calcium, sodium, and potassium, do not explain this association. Unidentified pathogenic mechanisms common to nephrolithiasis and hypertension may be responsible for the development of both disorders.

Adult↗

PubMed1998

Nephrolithiasis and risk of hypertension.

A positive association between nephrolithiasis and blood pressure has been suggested in previous studies. However, controversy remains, due to methodological problems in some of the previous studies and absence of prospective data. We evaluated the relationship between nephrolithiasis and the risk of hypertension in a cohort of 51,529 men followed prospectively for 8 years. Information was obtained by biennial mailed questionnaires. At baseline in 1986, 4111 (8.0%) subjects reported a history of nephrolithiasis and 11,623 (22.6%) a diagnosis of hypertension. A positive association was found between the two disorders (age adjusted odds ratio [OR]: 1.31; 95% confidence interval [CI]: 1.30 to 1.32). Among men who reported both disorders, 79.5% reported that the occurrence of nephrolithiasis was prior to or concomitant with the diagnosis of hypertension. Among men without hypertension at baseline, the odds ratio for incident hypertension in men with a history of nephrolithiasis compared with those without was 1.29 (95% CI: 1.12 to 1.41; adjusted for age, body mass index, and intake of calcium, sodium, potassium, magnesium, and alcohol). The occurrence of incident nephrolithiasis during follow-up was similar in men with hypertension at baseline compared with that in men without (adjusted OR: 0.99, 95% CI: 0.82 to 1.21). These data support the hypothesis that prior occurrence of nephrolithiasis increases the risk of subsequent hypertension.

Adult↗

PubMed1998

Body size and risk of kidney stones.

A variety of factors influence the formation of calcium oxalate kidney stones, including gender, diet, and urinary excretion of calcium, oxalate, and uric acid. Several of these factors may be related to body size. Because men on average have a larger body size and a threefold higher lifetime risk of stone formation than women, body size may be an important risk factor for calcium oxalate stone formation. The association between body size (height, weight, and body mass index) and the risk of kidney stone formation was studied in two large cohorts: the Nurses' Health Study (NHS; n = 89,376 women) and the Health Professionals Follow-up Study (HPFS; n = 51,529 men). Information on body size, kidney stone formation, and other exposures of interest was obtained by mailed questionnaires. A total of 1078 incident cases of kidney stones in NHS during 14 yr of follow-up and a total of 956 cases in HPFS during 8 yr of follow-up were confirmed. In both cohorts, the prevalence of a stone disease history and the incidence of stone disease were directly associated with weight and body mass index. However, the magnitude of the associations was consistently greater among women. Specifically, the age-adjusted prevalence odds ratio for women with body mass index > or = 32 kg/m2 compared with 21 to 22.9 kg/m2 was 1.76 (95% confidence interval, 1.50 to 2.07), but 1.38 (95% confidence interval, 1.16 to 1.65) for the same comparison in men. For incident stone formation, the multivariate relative risks for the similar comparisons were 1.89 (1.51 to 2.36) for women and 1.19 (0.83 to 1.70) in men. Height was inversely associated with the prevalence of stone disease but was not associated with incident stone formation. These results suggest that body size is associated with the risk of stone formation and that the magnitude of risk varies by gender. Additional studies are necessary to determine whether a reduction in body weight decreases the risk of stone formation, particularly in women.

Adult↗

PubMed1997

Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women.

BACKGROUND: Calcium intake is believed to play an important role in the formation of kidney stones, but data on the risk factors for stone formation in women are limited. OBJECTIVE: To examine the association between intake of dietary and supplemental calcium and the risk for kidney stones in women. DESIGN: Prospective cohort study with 12-year follow-up. SETTING: Several U.S. states. PARTICIPANTS: 91,731 women participating in the Nurses' Health Study I who were 34 to 59 years of age in 1980 and had no history of kidney stones. MEASUREMENTS: Self-administered food-frequency questionnaires were used to assess diet in 1980, 1984, 1986, and 1990. The main outcome measure was incident symptomatic kidney stones. RESULTS: During 903,849 person-years of follow-up, 864 cases of kidney stones were documented. After adjustment for potential risk factors, intake of dietary calcium was inversely associated with risk for kidney stones and intake of supplemental calcium was positively associated with risk. The relative risk for stone formation in women in the highest quintile of dietary calcium intake compared with women in the lowest quintile was 0.65 (95% CI, 0.50 to 0.83). The relative risk in women who took supplemental calcium compared with women who did not was 1.20 (CI, 1.02 to 1.41). In 67% of women who took supplemental calcium, the calcium either was not consumed with a meal or was consumed with meals whose oxalate content was probably low. Other dietary factors showed the following relative risks among women in the highest quintile of intake compared with those in the lowest quintile: sucrose, 1.52 (CI, 1.18 to 1.96); sodium, 1.30 (CI, 1.05 to 1.62); fluid, 0.61 (CI, 0.48 to 0.78); and potassium, 0.65 (CI, 0.51 to 0.84). CONCLUSIONS: High intake of dietary calcium appears to decrease risk for symptomatic kidney stones, whereas intake of supplemental calcium may increase risk. Because dietary calcium reduces the absorption of oxalate, the apparently different effects caused by the type of calcium may be associated with the timing of calcium ingestion relative to the amount of oxalate consumed. However, other factors present in dairy products (the major source of dietary calcium) could be responsible for the decreased risk seen with dietary calcium.

Absorption↗

PubMed1997

Renal vasculitis with HIV seropositivity: potential manifestation of cytomegalovirus infection.

The associations among human immunodeficiency virus (HIV) infection, focal segmental glomerulosclerosis, and its variant, "collapsing glomerulopathy," often leading to chronic renal failure, are well described. HIV-seropositive patients may also develop a variety of immune complex-mediated glomerular diseases, including postinfectious glomerulonephritis, IgA nephropathy, and membranoproliferative glomerulonephritis. Herein we describe a case of pauci-immune necrotizing renal vasculitis in an HIV-seropositive patient, thereby expanding the differential diagnosis of acute renal failure in this setting.

Cytomegalovirus Infections↗

PubMed1997

Family history and risk of kidney stones.

Kidney stones develop more frequently in individuals with a family history of kidney stones than in those without a family history; however, little information is available regarding whether the increased risk is attributable to genetic factors, environmental exposures, or some combination. In this report, the relation between family history and risk of kidney stone formation was studied in a cohort of 37,999 male participants in the Health Professionals Follow-up Study. Information on family history, kidney stone formation, and other exposures of interest, including dietary intake, was obtained by mailed questionnaires. A family history of kidney stones was much more common in men with a personal history of stones at baseline in 1986 than in those without a history of stones (age-adjusted prevalence odds ratio, 3.16; 95% confidence interval [CI], 2.90 to 3.45). During 8 yr of follow-up, 795 incident cases of stones were documented. After adjusting for a variety of risk factors, the relative risk of incident stone formation in men with a positive family history, compared with those without, was 2.57 (95% CI, 2.19 to 3.02). Family history did not modify the inverse association between dietary calcium intake and the risk of stone formation. These results suggest that a family history of kidney stones substantially increases the risk of stone formation. In addition, these data suggest that dietary calcium restriction may increase the risk of stone formation, even among individuals with a family history of kidney stones.

Adult↗